Enhancement of Solar Cell Performance with Layered Filler Graphite for Natural Dye Sensitized Solar Cell

Enhancement of Solar Cell Performance with Layered Filler Graphite for Natural Dye Sensitized Solar Cell | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Enhancement of Solar Cell Performance with Layered Filler Graphite for Natural Dye Sensitized Solar Cell Kumari Pooja, Shivansh Tripathi, Anshu Maurya, Priyanka Chawla, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7398761/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 11 You are reading this latest preprint version Abstract A dye-sensitized solar cell (DSSC) consists of four crucial components: a photoanode, electrolyte, sensitizer, and photocathode. The stability, efficiency, and sustainability of a DSSC rely on these components. In this study, a biopolymer (chitosan) with graphite filler has been utilized as the electrolyte system to address sealing and leakage issues associated with liquid electrolytes. Chitosan, with its β(1–4) linked 2-amino-deoxy-D-glucopyranose units, exhibits a polycationic character that enhances anionic interactions, forming a polyelectrolyte complex. Furthermore, chitosan is biodegradable, eco-friendly, biocompatible, and non-toxic, making it a sustainable choice. The TiO₂ working electrode has been improved with CuO nanopowder to minimize the inherent energy barrier. A cocktail dye, prepared from beetroot and spinach dyes in a 1:1 ratio, is used as the sensitizer, replacing synthetic dyes and enhancing the eco-friendliness of the fabricated DSSC. The reported solar conversion efficiency is approximately 2.3%, with a fill factor of 54%, under an irradiation of 100 mW/cm². Dye Sensitized Solar Cell (DSSC) Chitosan graphite fiiler co-sensitizer and polymer electrolyte Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Introduction Energy is an essential part of our daily lives, influencing every aspect of our existence. The increasing population, industrialization, and higher living standards have led to a high global energy demand. This demand has put undue pressure on the environment, as traditional non-renewable energy sources like fossil fuels, gas, and oil cause pollution. Solar energy is the most abundant renewable energy source, providing energy to the world without harming the environment. Solar cells have been developed to harness solar energy and provide sustainable electricity. However, silicon solar cells, which are currently in use, have high manufacturing costs and are not environmental friendly, limiting their widespread adoption. The introduction of dye-sensitized solar cells (DSSCs) by Grätzel in 1991 marked a significant advancement and presented new possibilities [ 1 – 2 ]. A DSSC consists of a photoanode, sensitizer electrolyte, and photocathode, each with shortcomings that hinder its overall performance. To address these issues, this study uses a polymer electrolyte. Polymer electrolytes are highly promising, not only for DSSCs but also for all-solid-state Li-ion and Li-metal batteries [ 3 – 4 ]. Here, we have used a biopolymer chitosan-based electrolyte to fabricate the DSSC. Chitosan is a widely abundant biopolymer known for its high thermal stability and rich content of OH groups, which provide improved affinity toward liquid electrolytes. Chitosan has β (1–4) linked 2-amino-deoxy-D-glucopyranose units, giving it a polycationic character that enhances anionic interactions and forms a polyelectrolyte complex. Chitosan is biodegradable, eco-friendly, biocompatible, and non-toxic, making it a sustainable choice [ 5 – 6 ]. In order to improve the ionic conductivity of the chitosan-based polymer electrolyte, graphite has been added as filler. The selection of conductive filler is crucial for producing highly conductive polymer composites. Graphite is economical, naturally abundant, and possesses a large surface area, providing a large interface that facilitates ion transport [ 7 ]. Graphite offers chemical stability, mechanical strength, thermal stability, and ion adsorption properties, all of which increase the conductivity of the electrolyte [ 8 – 9 ]. The efficiency of a DSSC is also influenced by the photoanode and the choice of sensitizer. TiO₂ is considered the most suitable semiconductor for DSSCs due to its high chemical stability and excellent photocatalytic efficiency [ 10 – 11 ]. However, its large energy band gap of 3 eV limits its application [ 12 ]. To overcome this limitation, we admixed CuO with TiO₂, resulting in a better spectral response by reducing the energy band gap to approximately 2.8 eV. The photochromic and electrochromic properties of CuO make it a suitable candidate for DSSCs [ 13 – 14 ]. Synthetic dyes, especially those based on ruthenium, yield the best results but are not environmental friendly [ 13 ]. Therefore, there is a need to shift towards sustainable alternatives. Eco-friendly DSSCs can be developed using natural dyes derived from fruits, leaves, and flowers, which are non-toxic, biodegradable, and affordable alternatives [ 15 – 16 ]. DSSCs have the potential to provide clean, sustainable energy and overcome the drawbacks of traditional silicon-based solar cells [17–19]. While numerous studies have explored polymer electrolytes and natural sensitizers in DSSCs, few have simultaneously focused on chitosan-based biopolymer electrolytes enhanced with graphite filler, combined with a CuO-TiO₂ photoanode and natural dye as sensitizers. The novelty of this work lies in the integrated use of (i) graphite as filler in chitosan based electrolyte to improve ionic conductivity and mechanical integrity, (ii) CuO-modified TiO₂ to narrow the band gap and enhance light harvesting, and (iii) natural dyes as sensitizers. Unlike previous research that often examines these components in isolation, this study demonstrates the synergistic effect of all three elements in a single DSSC. The present study aims to improve efficiency of the fabricated DSSC while maintaining environmental compatibility. This approach presents a cost-effective and biodegradable alternative to conventional DSSCs, contributing meaningfully to the on-going transition toward green energy technologies. The schematic representation of a DSSC is depicted in Fig. 1 . Materials Graphite powder, Chitosan (medium molecular weight), Lithium iodide (LiI), Iodine (I₂), Ethylene carbonate (EC), Propylene carbonate (PC), Titanium isopropoxide, Ti[OCH(CH₃)₂]₄, Copper(II) chloride dihydrate (CuCl₂·6H₂O), Glacial acetic acid, Sodium hydroxide (NaOH), Nitric acid (HNO₃, 70%), Propanol, Fresh beetroot (Beta vulgaris), Fresh spinach leaves (Spinacia oleracea), Ethanol (analytical grade), Deionized water, Indium tin oxide (ITO) coated glass substrates (15–20 Ω/cm²) and Platinum Experimental Preparation of Graphite Nanoparticles Through the Retsch PM 100 ball milling method, graphite nanopowder to be used as filler was prepared. 4 grams of graphite were processed and then left in a planetary ball mill for 52 hours at room temperature at a rotation speed of 300 rpm. All process was similar to our previous work [20]. Preparation of polymer electrolyte The chitosan-based polymer electrolyte film was made using the tried-and-true solution cast technique. First, a suitable quantity of chitosan and LiI:I 2 were dissolved in 100 mL of 1% acetic acid. The mixture was then thoroughly mixed with ethylene carbonate (EC) and propylene carbonate (PC) filler over the course of 7 hours. Finally, the mixture containing chitosan, LiI:I 2 (redox couple), graphite, and EC and PC was casted into a polypropylene dish. The polymer electrolyte sheet without solvent was developed by slow evaporation at room temperature and drying in vacuum. The Fig. 2 demonstrates the preparation method of polymer electrolyte. Preparation of TiO-CuO photoelectrode The TiO 2 and CuO nanopowders were made using the sol-gel technique. Drop by drop, Ti [OCH (CH 3 ) 2 ] 4 was added to propanol to make the TiO 2 colloidal solution. After adding deionized water and letting it settle for five minutes, a white precipitate started to form. One milliliter of 70% HNO 3 was then added to the mixture. The TiO 2 colloidal solution was obtained by allowing the propanol and a little amount of water to evaporate for 15 minutes at 80ºC while stirring. An aqueous solution was mixed with 0.2 M CuCl 2 •6H 2 O and 1 ml of glacial acetic acid to make the CuO colloidal solution. The mixture was heated to 100 o C while being stirred constantly. After adding 8 M NaOH to the heated solution until the pH was almost 7, a significant precipitate formed, producing a CuO colloidal solution. The CuO solution was gradually added to the TiO 2 colloidal solution while the mixture was vigorously stirred for six hours in order to produce the TiO 2 -CuO admixed nanopowder. TiO 2 -CuO nanopowder was subsequently obtained by calcining and drying the resulting gel at 450ºC. Extraction and Purification of Natural dyes Fresh beetroot pieces (50 gm) and fresh spinach leaves (50 gm) were crushed in a mortar after being cleaned with deionized water. After that, they were each submerged in 100 mL of ethanol for a week in separate beakers. The solutions were then filtered, and a rotavapor operating at 40°C was used to concentrate the filtrates. Using a 1:1 volume ratio, the resultant dye solutions were mixed to make a natural cocktail dye sensitizer for DSSC. Chromatographic methods were utilized to purify the dyes that were extracted. The extracted dyes and prepared cocktail dye to be used as a co-sensitizer are shown in Fig. 3 . Fabrication of DSSC The ITO conductive glass plates, highlighting a sheet resistance extending from 15 to 20 Ω/cm 2 , experienced introductory cleaning in a cleanser arrangement utilizing an ultrasonic shower for 15 minutes. Hence, they were washed successively with water, ethanol, and dried in a stove. A glue of TiO 2 - CuO was at that point connected onto the conductive glass utilizing the doctor-blade procedure and strengthened at 150°C. The prepared photoanode was immersed in the cocktail dye in a petri dish and kept undisturbed for 24 hours. With platinum acting as the cathode, the synthesis polymer electrolyte was sandwiched between the photoanode and photocathode. The fabrication is done as shown in Fig. 4 . Structural Characterization Scanning electron microscopy (SEM) with a Carl Zeiss Evo 18 equipment and X-ray diffraction (XRD) with a Philips PW 1710 diffractometer were used to characterize the structure and morphology of the developed polymer electrolyte film and nanomaterials. Using a Perkin Elmer device, Fourier-transform infrared spectroscopy (FTIR) analysis was done. A Biologic SP-150 device was used for all electrochemical investigations. The light source was a xenon-mercury lamp from Oriel Corporation in the United States, with an intensity adjustment and fixation set at 100 mW/cm 2 . Results and Discussion Sharp, powerful peaks can be seen in the XRD pattern of the pure chitosan film at 14.2° and 23°, respectively. When filler graphite is added to the polymer matrix, the region of the unique peaks of both graphite and chitosan becomes broader and their intensity diminishes. The observed effect suggests a rise in the level of amorphousity, an essential component in augmenting ionic conductivity. Figure 5 illustrates the XRD of the polymer electrolyte system. The SEM image in Fig. 6 of chitosan with graphite filler displays a markedly distinct shape in comparison to pure chitosan. The surface exhibits a generally smoother texture, with discernible dark areas signifying the presence of scattered graphite particles inside the chitosan matrix. The addition of graphite filler has probably decreased the surface roughness and altered the crystalline domains of chitosan, hence increasing the amorphous portion of the composite. This is apparent from the more consistent surface and the lack of distinct fibrous patterns observed in the pure chitosan image. The graphite distribution is uniform, indicating strong compatibility between the polymer and the filler. The structural modification resulting from graphite incorporation is anticipated to enhance ion conductivity and overall material characteristics, rendering the composite appropriate for uses like polymer electrolytes. The spectrum of pure chitosan exhibits distinctive peaks, including a wide band at around 3400 cm⁻¹, associated with O–H and N–H stretching vibrations, and bands near 1650 cm⁻¹ and 1590 cm⁻¹, which correspond to amide I and amide II groups, respectively. The peaks signify the crystalline structure of chitosan, where robust hydrogen bonding within the polymer matrix enhances this crystallinity, hence restricting ion conduction (Fig. 7 a). Conversely, the spectrum of pure graphite exhibits a lack of notable bands in the high wavenumber range (above 3000 cm⁻¹), indicating its non-polar and inert characteristics. Characteristic bands emerge about 1580 cm⁻¹, indicative of C = C stretching in the graphite layers, underscoring its conductive qualities attributed to delocalized π-electrons that enhance charge transfer when integrated into a composite (Fig. 7 b). In the chitosan-based polymer electrolyte spectrum with graphite filler, notable alterations are observed, including a decrease in intensity and broadening of the O–H stretching vibration near 3400 cm⁻¹, signifying diminished hydrogen bonding resulting from interactions between graphite and the polymer chains (Fig. 7 c). This disruption augments the amorphous characteristics of the polymer electrolyte system, hence enhancing ion mobility. Moreover, the amide I and II peaks at approximately 1650 cm⁻¹ and 1590 cm⁻¹ exhibit shifts and broadening, indicating interactions between graphite and chitosan. New bands in the region (below 1500 cm⁻¹) emerge from the graphite filler, demonstrating its effective integration into the polymer matrix. Figure 8 demonstrates the ambient AC conductivity of both pure chitosan and chitosan electrolyte filled with graphite. The conductivity of pure chitosan is 10⁻⁷ S/cm, while chitosan that has been filled with graphite has a conductivity of 10⁻⁴ S/cm. Up to 5 kHz, the conductivity increases linearly. The power law indicates that the sample's AC conductivity is frequency-dependent. \(\:{\sigma\:}^{ac}={A\omega\:}^{\rho\:}\) A is a constant and ρ is the frequency exponent (where ρ < 1) in the expression above. Over a broad frequency range, the ωρ power law is frequently seen in a variety of materials, including polymers. The XRD pattern of the TiO₂-CuO admixed nanopowder illustrated in Fig. 9 showed sharp, well-defined peaks, confirming the crystalline nature of the material. The absence of any additional peaks indicated that no new phases or compounds were formed during the synthesis, suggesting that both TiO₂ and CuO retained their structural integrity. This crystalline quality is vital for effective electron transport in dye-sensitized solar cells (DSSCs), as it aids in reducing recombination losses and improving overall efficiency. The nanocrystalline structure of the prepared nanomaterial is observe in the SEM image shown in Fig. 10 . Through the use of SEM and Scherer's equation for the diffraction peaks, the average grain size was determined to be between 20 and 35 nm. The vast amount of dye molecules that can be absorbed by the small grain size will ultimately lead to a high efficiency of the DSSC. It is also evident from the SEM image that CuO is present over the TiO 2 in the form of an island rather than reacting with it to generate a new structure. The increased photoactive area caused by the nanocrystalline nature will raise efficiency of the cell. The behaviour of the TiO 2 -CuO photoanode coated with cocktail dye is study via absorption spectra shown in Fig. 11 . The enhanced interaction between TiO 2 -CuO and cocktail dye is considered to be responsible for the significant increase in the light absorption spectrum, since it facilitates charge transfer and lowers the recombination rate. The capacity of CuO to function as an electron-acceptor amplifies the photocatalytic efficacy of TiO 2 . Furthermore, suitable conduction band of CuO promotes the facile transfer of photogenerated electrons from TiO 2 , hence facilitating effective charge separation. Figure 12 illustrates the FTIR spectra of natural dyes: (a) beetroot, (b) spinach, and (c) cocktail. There are three significant peaks in the spectrum that are linked to beetroot dye: 1028, 1565, and 3248 cm − 1 . Stretching vibrations in C-O bonds are represented by the peak at 1028 cm − 1 , whereas stretching vibrations in C-C and O-H bonds are shown by the wider peaks at 1565 and 3248 cm − 1 , respectively. There are two peaks in the spinach dye spectrum: 1523 cm-1 and 2356 cm − 1 , representing the characteristic peaks of chlorophyll a (N-H deformation) and chlorophyll b (N-H stretching), respectively. Additionally, a peak appears at 3352 cm- 1 corresponding to the O-H group, as ethanol was used in the extraction process. Prominent peaks associated with C-O and C-H bond stretching is observed at 1742 cm − 1 and 2859 cm − 1 , respectively. Notably, in the spectrum of the cocktail containing betacyanin and chlorophyll, no suppression effect on either dye is observed, as indicated by the presence of prominent peaks. Figure 13 depicts the light absorption characteristics of betacyanin, chlorophyll, and the cocktail dye coated TiO 2 photoelectrodes. Each dye exhibits distinctive absorption wavelengths attributed to their unique subatomic structures. Betacyanin dye absorbs light primarily in the 550 nm range, while chlorophyll absorbs light around 440 nm. The combination of both dyes results in an enhancement of absorption wavelengths, particularly in the range of about 660 nm. This broader absorption spectrum resulting from the mixing of dyes increases the ability of the dyes to absorb photons from sunlight, leading to the continual regeneration of electrons and, in the end, enhancing performance of the DSSC. photoelectrodes on ITO glass substrate. Following the characterization of the prepared polymer electrolyte and natural dye, they were employed to assemble the fabricated DSSC, utilizing platinum as the counter electrode. Figure 14 illustrates a typical J-V curve of the fabricated DSSC. The achieved conversion efficiency was 2.5%, accompanied by a fill factor of 54%. The photocurrent (Isc) was measured at 8.2 mA/cm 2 , while the photovoltage (Voc) was recorded at 0.680 V. In a previous study by Chawla et al. (2018), DSSCs were fabricated using chitosan-based polymer electrolyte with TiO 2 filler and anthocyanin natural dye, resulting in a conversion efficiency of 1.8%. Table 1 presents a comparison of the different polymer electrolyte systems based on chitosan that are utilized in DSSCs, along with their conductivity and the efficiency of the fabricated DSSCs. In the current work, the incorporation of carbon fillers, namely graphite significantly enhanced the conductivity of the polymer electrolyte system from 10 − 7 to 10 − 4 S/cm. This enhancement in conductivity led to an improved efficiency of 2.3%, which is noteworthy in the context of natural dye-sensitized solar cells. Table – 1. Comparation of DSSCs’ performances utilizing chitosan as host polymer and indifferent fillers. S.No Electrolyte system Conductivity FF (Fill Factor) Photoanode Photoc–athode Dye ɳ (Efficiency) Ref. 1. Chitosan/TiO 2 10 − 5 S/cm 53% TiO 2 -WO Pt Natural dye 1.8% [21] 2. Chitosan/LiClO 4 10 − 4 S/cm 15% ZnO Pt Organic dye (RB) 0.05% [22] 3. Chitosan 44.59% ZnO/ZnS Pt N719 1.6% [23] 4. Chitosan/PVDF/HFP 5.367×10 − 4 S/cm 35% TiO 2 Pt N719 1.23% [24] 5. Chitosan/Nal 1.11X10 − 4 S/cm 30% TiO 2 Pt N719 0.06% [25] 6. Chitosa/PEO/NH 4 I 3.66X10 − 6 S/cm 69% TiO 2 /AgNP Pt N3 1.13% [26] The cell performance of the fabricated DSSCs with a TiO₂-CuO photoelectrode sensitized with a natural cocktail dye is displayed in Fig. 14 . The efficiency of a DSSC using pure chitosan as a polymer electrolyte was 0.50% and fill factor was 45%, whereas adding graphite filler increased the efficiency to 2.3% and fill factor reported to be 54%. The total resistance of pure chitosan electrolyte is elevated due to its crystalline structure, which restricts ionic mobility and the diffusion of iodine/triiodide ions (I − /I 3 − ). The resistance of the pure chitosan-based DSSC is recorded at 712 Ω (Fig. 15 a). Nevertheless, the use of graphite as a filler into the chitosan-based polymer electrolyte results in a substantial reduction in resistance to 355 Ω (Fig. 15 b). The decrease in resistance is ascribed to the graphite filler, which interferes with the crystalline domains in the chitosan matrix, so improving its amorphous structure. The augmented amorphous characteristics promote ion transport and elevate ionic conductivity and diffusion coefficients, hence improving DSSC performance. (a) Pure Chitosan and (b) Chitosan with graphite as filler Conclusion In this study, we used a chitosan-based polymer electrolyte with graphite filler to fabricate a natural dye-sensitized solar cell (DSSC). According to our research, adding the chitosan polymer electrolyte improved the cell's stability, while adding the graphite filler raised the polymer electrolyte system's conductivity. The photocatalytic effectiveness of the photoanode was enhanced by the addition of CuO to TiO₂. Additionally, higher charge transfer between the dye molecules and the TiO₂-CuO surface was made possible by the cocktail dye's stronger complexation with the surface. Consequently, this dye was able to convert input photons into electrons with greater efficiency. Declarations Conflict interest: There are no conflicts to declare. Acknowledgements Authors are thankful to CSTUP ( Ref. no. CST/ENV/D-668) (council of science &technology, U.P.) for financial support. Author’s Contribution Author Mridula Tripathi proposed an experimental approach, author Priyanka Chawla, Anshu Maurya, Shivansh Tripathi and Kumari Pooja carried out synthesis of samples and their electrochemical study; all authors are participated in preparation of the manuscript and discussion of results. References Dhariwal S (2021). Importance of natural composite dye sensitized solar cell (DSSC) to generate high efficiency and non-toxic energy. Alliance College of Engineering and Design . Gratzel M (2003). Dye-sensitized solar cell. J Photochem Photobiol C 4:145–153. https://doi.org/10.1016/S1389-5567(03)00026-1. Devadiga D, Selvakumar M, Shetty P, et al. (2021). Dye-sensitized solar cell for indoor applications: A mini-review. J Electron Mater 50:3187–3206. https://doi.org/10.1007/s11664-021-08854-3. Song Z, Chen F, Martinez-Ibañez M, et al. (2023). A reflection on polymer electrolytes for solid-state lithium metal batteries. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7398761","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":504448397,"identity":"4e1b84b4-bdbe-4045-b74f-bb8bd777a18e","order_by":0,"name":"Kumari Pooja","email":"","orcid":"","institution":"University of Allahabad","correspondingAuthor":false,"prefix":"","firstName":"Kumari","middleName":"","lastName":"Pooja","suffix":""},{"id":504448399,"identity":"65409531-b382-484c-8843-f03e3684b7aa","order_by":1,"name":"Shivansh Tripathi","email":"","orcid":"","institution":"National Atmospheric Research 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Tripathi","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA2ElEQVRIiWNgGAWjYLCCBwwHgCQziJCQIU5LAlgLWwJICw8pWngMQGzCWszZzx58kFBzR153ds/nVzdqLHgY2A8f3YBPi2VPXrJBwrFnhtvunN1mnXMM6DCetLQb+LQYHMgxk0hgO5xgdiN3m3EOG1CLBI8Zfi3n3wC1/ANpyXlmnPOPGC03gLYktoG1MD/ObSNKyxtjg8Q+kF+OmTHn9knwsBH0y/kcwwcfvt2RN7vd/Phzzrc6OX72w8fwakEACQY2CRDNRpxyiBbmD8SrHgWjYBSMgpEEAPmxTbWFpyLcAAAAAElFTkSuQmCC","orcid":"","institution":"University of Allahabad","correspondingAuthor":true,"prefix":"","firstName":"Mridula","middleName":"","lastName":"Tripathi","suffix":""}],"badges":[],"createdAt":"2025-08-18 10:38:36","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7398761/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7398761/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":90125103,"identity":"dd367720-1e60-444a-aa08-8ba6a9c227d7","added_by":"auto","created_at":"2025-08-28 18:52:28","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":65834,"visible":true,"origin":"","legend":"\u003cp\u003eDiagrammatic representation of a dye-sensitized solar cellTop of Form\u003c/p\u003e","description":"","filename":"image1.png","url":"https://assets-eu.researchsquare.com/files/rs-7398761/v1/c9559e9123af2198f85d81bc.png"},{"id":90125104,"identity":"5756fc85-b5f4-4291-9f3c-d49e62f1dfb3","added_by":"auto","created_at":"2025-08-28 18:52:28","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":36442,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic diagram showing preparation of Chitosan based polymer electrolyte incorporated with graphite as filler\u003c/p\u003e","description":"","filename":"image2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7398761/v1/cc10fa35d27770336e18c2d2.jpeg"},{"id":90125105,"identity":"fe3c894f-ea72-48fb-8a29-403b25c35792","added_by":"auto","created_at":"2025-08-28 18:52:28","extension":"jpeg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":11304,"visible":true,"origin":"","legend":"\u003cp\u003eA- Dye extracted from spinach, B- Dye extracted from beetroot and C- Cocktail dye\u003c/p\u003e","description":"","filename":"image3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7398761/v1/82946e05bf5bb4fe8d5e01ea.jpeg"},{"id":90125106,"identity":"1c68f65c-b557-491c-b524-de17cb3035e6","added_by":"auto","created_at":"2025-08-28 18:52:28","extension":"jpeg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":35511,"visible":true,"origin":"","legend":"\u003cp\u003eFabrication of Dye Sensitized Solar Cell\u003c/p\u003e","description":"","filename":"image4.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7398761/v1/19b0d139441e37fdf927bb64.jpeg"},{"id":90125118,"identity":"1e7a23dc-9344-4ea0-a186-6769a7092050","added_by":"auto","created_at":"2025-08-28 18:52:28","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":123671,"visible":true,"origin":"","legend":"\u003cp\u003eXRD pattern of the polymer electrolyte system\u003c/p\u003e","description":"","filename":"image5.png","url":"https://assets-eu.researchsquare.com/files/rs-7398761/v1/15b4aad2238178fdf44b7f6c.png"},{"id":90125947,"identity":"a843e6a5-4771-4102-b013-d132c6d6c96d","added_by":"auto","created_at":"2025-08-28 19:08:28","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":137289,"visible":true,"origin":"","legend":"\u003cp\u003eSEM of (a) Pure Chitosan (b) 98 {80 Chitosan - 20 LiI: I\u003csub\u003e2\u003c/sub\u003e}: 2 graphite\u003c/p\u003e","description":"","filename":"image6.png","url":"https://assets-eu.researchsquare.com/files/rs-7398761/v1/579fa32c646bfa4e6ebc2868.png"},{"id":90125515,"identity":"030ef92e-b52a-419f-8eec-a4800860b35e","added_by":"auto","created_at":"2025-08-28 19:00:28","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":66009,"visible":true,"origin":"","legend":"\u003cp\u003eFTIR of (a) Pure Chitosan (b) Graphite and (c) 98 {80 Chitosan - 20 LiI: I\u003csub\u003e2\u003c/sub\u003e}: 2 graphite\u003c/p\u003e","description":"","filename":"image7.png","url":"https://assets-eu.researchsquare.com/files/rs-7398761/v1/17d0b1eb91b41a67d901fb67.png"},{"id":90125123,"identity":"ddafbaa0-4fb6-4897-86ee-3359deb5a7aa","added_by":"auto","created_at":"2025-08-28 18:52:28","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":77553,"visible":true,"origin":"","legend":"\u003cp\u003eVariation of ac conductivity of the films with frequency\u003c/p\u003e","description":"","filename":"image8.png","url":"https://assets-eu.researchsquare.com/files/rs-7398761/v1/314b6b34655b837ab977d2b7.png"},{"id":90125107,"identity":"cde105ec-a303-4506-8c76-eb89e69acab5","added_by":"auto","created_at":"2025-08-28 18:52:28","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":69495,"visible":true,"origin":"","legend":"\u003cp\u003eXRD pattern of TiO\u003csub\u003e2\u003c/sub\u003e-CuO nanopowder\u003c/p\u003e","description":"","filename":"image9.png","url":"https://assets-eu.researchsquare.com/files/rs-7398761/v1/979a8f142d9db0b5a749fcbe.png"},{"id":90125115,"identity":"08c97e14-7e34-4eb2-8850-dce32ab14a4a","added_by":"auto","created_at":"2025-08-28 18:52:28","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":77702,"visible":true,"origin":"","legend":"\u003cp\u003eSEM image of (a) ns- TiO\u003csub\u003e2 \u003c/sub\u003e(b) ns- TiO\u003csub\u003e2\u003c/sub\u003e-CuO nanocomposite\u003c/p\u003e","description":"","filename":"image10.png","url":"https://assets-eu.researchsquare.com/files/rs-7398761/v1/2574a3b865b1fce067f25f3a.png"},{"id":90125518,"identity":"0ea759f5-2637-4c43-9b16-cd1060e19c15","added_by":"auto","created_at":"2025-08-28 19:00:28","extension":"png","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":59500,"visible":true,"origin":"","legend":"\u003cp\u003eAbsorption spectra of cocktail dye coated photoelectrode on ITO glass substrate (a) TiO\u003csub\u003e2\u003c/sub\u003e (b) TiO\u003csub\u003e2\u003c/sub\u003e-CuO nanocompositeTop of Form\u003c/p\u003e","description":"","filename":"image11.png","url":"https://assets-eu.researchsquare.com/files/rs-7398761/v1/cf4c1f8b2634d4928c521af7.png"},{"id":90125126,"identity":"502fda07-5906-4ae0-8f03-92f3ca3e44e3","added_by":"auto","created_at":"2025-08-28 18:52:28","extension":"jpeg","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":101376,"visible":true,"origin":"","legend":"\u003cp\u003eFTIR spectra of natural dyes: (a) Beetroot, (b) spinach, and (c) cocktail.\u003c/p\u003e","description":"","filename":"image12.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7398761/v1/aa14442f7268a4347f8c0130.jpeg"},{"id":90125948,"identity":"0215947f-83d0-49e7-b91b-924e2d6b8801","added_by":"auto","created_at":"2025-08-28 19:08:28","extension":"png","order_by":13,"title":"Figure 13","display":"","copyAsset":false,"role":"figure","size":74351,"visible":true,"origin":"","legend":"\u003cp\u003eThe absorption spectra of the cocktail dye coated on TiO\u003csub\u003e2\u003c/sub\u003e, betacyanin, and chlorophyll\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;photoelectrodes on ITO glass substrate.\u003c/p\u003e","description":"","filename":"image13.png","url":"https://assets-eu.researchsquare.com/files/rs-7398761/v1/db8167aa66c421696fbf0636.png"},{"id":90125140,"identity":"357fd773-415c-403d-84d0-2888653ab01c","added_by":"auto","created_at":"2025-08-28 18:52:29","extension":"jpeg","order_by":14,"title":"Figure 14","display":"","copyAsset":false,"role":"figure","size":36846,"visible":true,"origin":"","legend":"\u003cp\u003eThe characteristic curves depicting the relationship between current density and cell potential of the fabricated DSSCs with DSSCs using various polymers electrolytes\u003c/p\u003e\n\u003cp\u003e(a) Pure Chitosan and (b) Chitosan with graphite as filler\u003c/p\u003e","description":"","filename":"image14.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7398761/v1/eec85523f52e9cea4e5ce9af.jpeg"},{"id":90125527,"identity":"c1f90a22-6a25-4841-907e-cfcfbcdb3546","added_by":"auto","created_at":"2025-08-28 19:00:29","extension":"png","order_by":15,"title":"Figure 15","display":"","copyAsset":false,"role":"figure","size":49292,"visible":true,"origin":"","legend":"\u003cp\u003eNyquist plot of fabricated DSSC with (a) Pure Chitosan (b) 98 {80 Chitosan - 20 LiI: I\u003csub\u003e2\u003c/sub\u003e}: 2 graphite\u003c/p\u003e","description":"","filename":"image15.png","url":"https://assets-eu.researchsquare.com/files/rs-7398761/v1/f1e6fb4eb31b9f835a94ee60.png"},{"id":90126186,"identity":"4b95c887-494b-4d0a-85ab-14eedafd9ef8","added_by":"auto","created_at":"2025-08-28 19:16:29","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1631826,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7398761/v1/db76d9ce-56f5-4566-97be-8d814a3c379a.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Enhancement of Solar Cell Performance with Layered Filler Graphite for Natural Dye Sensitized Solar Cell","fulltext":[{"header":"Introduction","content":"\u003cp\u003eEnergy is an essential part of our daily lives, influencing every aspect of our existence. The increasing population, industrialization, and higher living standards have led to a high global energy demand. This demand has put undue pressure on the environment, as traditional non-renewable energy sources like fossil fuels, gas, and oil cause pollution. Solar energy is the most abundant renewable energy source, providing energy to the world without harming the environment. Solar cells have been developed to harness solar energy and provide sustainable electricity. However, silicon solar cells, which are currently in use, have high manufacturing costs and are not environmental friendly, limiting their widespread adoption. The introduction of dye-sensitized solar cells (DSSCs) by Gr\u0026auml;tzel in 1991 marked a significant advancement and presented new possibilities [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eA DSSC consists of a photoanode, sensitizer electrolyte, and photocathode, each with shortcomings that hinder its overall performance. To address these issues, this study uses a polymer electrolyte. Polymer electrolytes are highly promising, not only for DSSCs but also for all-solid-state Li-ion and Li-metal batteries [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Here, we have used a biopolymer chitosan-based electrolyte to fabricate the DSSC. Chitosan is a widely abundant biopolymer known for its high thermal stability and rich content of OH groups, which provide improved affinity toward liquid electrolytes. Chitosan has β (1\u0026ndash;4) linked 2-amino-deoxy-D-glucopyranose units, giving it a polycationic character that enhances anionic interactions and forms a polyelectrolyte complex. Chitosan is biodegradable, eco-friendly, biocompatible, and non-toxic, making it a sustainable choice [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eIn order to improve the ionic conductivity of the chitosan-based polymer electrolyte, graphite has been added as filler. The selection of conductive filler is crucial for producing highly conductive polymer composites. Graphite is economical, naturally abundant, and possesses a large surface area, providing a large interface that facilitates ion transport [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Graphite offers chemical stability, mechanical strength, thermal stability, and ion adsorption properties, all of which increase the conductivity of the electrolyte [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe efficiency of a DSSC is also influenced by the photoanode and the choice of sensitizer. TiO₂ is considered the most suitable semiconductor for DSSCs due to its high chemical stability and excellent photocatalytic efficiency [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. However, its large energy band gap of 3 eV limits its application [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. To overcome this limitation, we admixed CuO with TiO₂, resulting in a better spectral response by reducing the energy band gap to approximately 2.8 eV. The photochromic and electrochromic properties of CuO make it a suitable candidate for DSSCs [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eSynthetic dyes, especially those based on ruthenium, yield the best results but are not environmental friendly [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Therefore, there is a need to shift towards sustainable alternatives. Eco-friendly DSSCs can be developed using natural dyes derived from fruits, leaves, and flowers, which are non-toxic, biodegradable, and affordable alternatives [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. DSSCs have the potential to provide clean, sustainable energy and overcome the drawbacks of traditional silicon-based solar cells [17\u0026ndash;19]. While numerous studies have explored polymer electrolytes and natural sensitizers in DSSCs, few have simultaneously focused on chitosan-based biopolymer electrolytes enhanced with graphite filler, combined with a CuO-TiO₂ photoanode and natural dye as sensitizers. The novelty of this work lies in the integrated use of (i) graphite as filler in chitosan based electrolyte to improve ionic conductivity and mechanical integrity, (ii) CuO-modified TiO₂ to narrow the band gap and enhance light harvesting, and (iii) natural dyes as sensitizers. Unlike previous research that often examines these components in isolation, this study demonstrates the synergistic effect of all three elements in a single DSSC.\u003c/p\u003e\u003cp\u003eThe present study aims to improve efficiency of the fabricated DSSC while maintaining environmental compatibility. This approach presents a cost-effective and biodegradable alternative to conventional DSSCs, contributing meaningfully to the on-going transition toward green energy technologies. The schematic representation of a DSSC is depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"Materials","content":"\u003cp\u003eGraphite powder, Chitosan (medium molecular weight), Lithium iodide (LiI), Iodine (I₂), Ethylene carbonate (EC), Propylene carbonate (PC), Titanium isopropoxide, Ti[OCH(CH₃)₂]₄, Copper(II) chloride dihydrate (CuCl₂\u0026middot;6H₂O), Glacial acetic acid, Sodium hydroxide (NaOH), Nitric acid (HNO₃, 70%), Propanol, Fresh beetroot (Beta vulgaris), Fresh spinach leaves (Spinacia oleracea), Ethanol (analytical grade), Deionized water, Indium tin oxide (ITO) coated glass substrates (15\u0026ndash;20 Ω/cm\u0026sup2;) and Platinum\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eExperimental\u003c/h2\u003e\u003cdiv id=\"Sec4\" class=\"Section3\"\u003e\u003ch2\u003ePreparation of Graphite Nanoparticles\u003c/h2\u003e\u003cp\u003eThrough the Retsch PM 100 ball milling method, graphite nanopowder to be used as filler was prepared. 4 grams of graphite were processed and then left in a planetary ball mill for 52 hours at room temperature at a rotation speed of 300 rpm. All process was similar to our previous work [20].\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\n\u003ch3\u003ePreparation of polymer electrolyte\u003c/h3\u003e\n\u003cp\u003eThe chitosan-based polymer electrolyte film was made using the tried-and-true solution cast technique. First, a suitable quantity of chitosan and LiI:I\u003csub\u003e2\u003c/sub\u003e were dissolved in 100 mL of 1% acetic acid. The mixture was then thoroughly mixed with ethylene carbonate (EC) and propylene carbonate (PC) filler over the course of 7 hours. Finally, the mixture containing chitosan, LiI:I\u003csub\u003e2\u003c/sub\u003e (redox couple), graphite, and EC and PC was casted into a polypropylene dish. The polymer electrolyte sheet without solvent was developed by slow evaporation at room temperature and drying in vacuum. The Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e demonstrates the preparation method of polymer electrolyte.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\n\u003ch3\u003ePreparation of TiO-CuO photoelectrode\u003c/h3\u003e\n\u003cp\u003eThe TiO\u003csub\u003e2\u003c/sub\u003e and CuO nanopowders were made using the sol-gel technique. Drop by drop, Ti [OCH (CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e]\u003csub\u003e4\u003c/sub\u003e was added to propanol to make the TiO\u003csub\u003e2\u003c/sub\u003e colloidal solution. After adding deionized water and letting it settle for five minutes, a white precipitate started to form. One milliliter of 70% HNO\u003csub\u003e3\u003c/sub\u003e was then added to the mixture. The TiO\u003csub\u003e2\u003c/sub\u003e colloidal solution was obtained by allowing the propanol and a little amount of water to evaporate for 15 minutes at 80\u0026ordm;C while stirring. An aqueous solution was mixed with 0.2 M CuCl\u003csub\u003e2\u003c/sub\u003e\u0026bull;6H\u003csub\u003e2\u003c/sub\u003eO and 1 ml of glacial acetic acid to make the CuO colloidal solution. The mixture was heated to 100\u003csup\u003eo\u003c/sup\u003eC while being stirred constantly. After adding 8 M NaOH to the heated solution until the pH was almost 7, a significant precipitate formed, producing a CuO colloidal solution. The CuO solution was gradually added to the TiO\u003csub\u003e2\u003c/sub\u003e colloidal solution while the mixture was vigorously stirred for six hours in order to produce the TiO\u003csub\u003e2\u003c/sub\u003e-CuO admixed nanopowder. TiO\u003csub\u003e2\u003c/sub\u003e-CuO nanopowder was subsequently obtained by calcining and drying the resulting gel at 450\u0026ordm;C.\u003c/p\u003e\n\u003ch3\u003eExtraction and Purification of Natural dyes\u003c/h3\u003e\n\u003cp\u003eFresh beetroot pieces (50 gm) and fresh spinach leaves (50 gm) were crushed in a mortar after being cleaned with deionized water. After that, they were each submerged in 100 mL of ethanol for a week in separate beakers. The solutions were then filtered, and a rotavapor operating at 40\u0026deg;C was used to concentrate the filtrates. Using a 1:1 volume ratio, the resultant dye solutions were mixed to make a natural cocktail dye sensitizer for DSSC. Chromatographic methods were utilized to purify the dyes that were extracted. The extracted dyes and prepared cocktail dye to be used as a co-sensitizer are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003eFabrication of DSSC\u003c/h2\u003e\u003cp\u003eThe ITO conductive glass plates, highlighting a sheet resistance extending from 15 to 20 Ω/cm\u003csup\u003e2\u003c/sup\u003e, experienced introductory cleaning in a cleanser arrangement utilizing an ultrasonic shower for 15 minutes. Hence, they were washed successively with water, ethanol, and dried in a stove. A glue of TiO\u003csub\u003e2\u003c/sub\u003e - CuO was at that point connected onto the conductive glass utilizing the doctor-blade procedure and strengthened at 150\u0026deg;C. The prepared photoanode was immersed in the cocktail dye in a petri dish and kept undisturbed for 24 hours. With platinum acting as the cathode, the synthesis polymer electrolyte was sandwiched between the photoanode and photocathode. The fabrication is done as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eStructural Characterization\u003c/h3\u003e\n\u003cp\u003eScanning electron microscopy (SEM) with a Carl Zeiss Evo 18 equipment and X-ray diffraction (XRD) with a Philips PW 1710 diffractometer were used to characterize the structure and morphology of the developed polymer electrolyte film and nanomaterials. Using a Perkin Elmer device, Fourier-transform infrared spectroscopy (FTIR) analysis was done. A Biologic SP-150 device was used for all electrochemical investigations. The light source was a xenon-mercury lamp from Oriel Corporation in the United States, with an intensity adjustment and fixation set at 100 mW/cm\u003csup\u003e2\u003c/sup\u003e.\u003c/p\u003e"},{"header":"Results and Discussion","content":"\u003cp\u003eSharp, powerful peaks can be seen in the XRD pattern of the pure chitosan film at 14.2\u0026deg; and 23\u0026deg;, respectively. When filler graphite is added to the polymer matrix, the region of the unique peaks of both graphite and chitosan becomes broader and their intensity diminishes. The observed effect suggests a rise in the level of amorphousity, an essential component in augmenting ionic conductivity. Figure\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e illustrates the XRD of the polymer electrolyte system. The SEM image in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e of chitosan with graphite filler displays a markedly distinct shape in comparison to pure chitosan. The surface exhibits a generally smoother texture, with discernible dark areas signifying the presence of scattered graphite particles inside the chitosan matrix. The addition of graphite filler has probably decreased the surface roughness and altered the crystalline domains of chitosan, hence increasing the amorphous portion of the composite. This is apparent from the more consistent surface and the lack of distinct fibrous patterns observed in the pure chitosan image. The graphite distribution is uniform, indicating strong compatibility between the polymer and the filler. The structural modification resulting from graphite incorporation is anticipated to enhance ion conductivity and overall material characteristics, rendering the composite appropriate for uses like polymer electrolytes.\u003c/p\u003e\u003cp\u003eThe spectrum of pure chitosan exhibits distinctive peaks, including a wide band at around 3400 cm⁻\u0026sup1;, associated with O\u0026ndash;H and N\u0026ndash;H stretching vibrations, and bands near 1650 cm⁻\u0026sup1; and 1590 cm⁻\u0026sup1;, which correspond to amide I and amide II groups, respectively. The peaks signify the crystalline structure of chitosan, where robust hydrogen bonding within the polymer matrix enhances this crystallinity, hence restricting ion conduction (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003ea). Conversely, the spectrum of pure graphite exhibits a lack of notable bands in the high wavenumber range (above 3000 cm⁻\u0026sup1;), indicating its non-polar and inert characteristics. Characteristic bands emerge about 1580 cm⁻\u0026sup1;, indicative of C\u0026thinsp;=\u0026thinsp;C stretching in the graphite layers, underscoring its conductive qualities attributed to delocalized π-electrons that enhance charge transfer when integrated into a composite (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003eb). In the chitosan-based polymer electrolyte spectrum with graphite filler, notable alterations are observed, including a decrease in intensity and broadening of the O\u0026ndash;H stretching vibration near 3400 cm⁻\u0026sup1;, signifying diminished hydrogen bonding resulting from interactions between graphite and the polymer chains (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003ec). This disruption augments the amorphous characteristics of the polymer electrolyte system, hence enhancing ion mobility. Moreover, the amide I and II peaks at approximately 1650 cm⁻\u0026sup1; and 1590 cm⁻\u0026sup1; exhibit shifts and broadening, indicating interactions between graphite and chitosan. New bands in the region (below 1500 cm⁻\u0026sup1;) emerge from the graphite filler, demonstrating its effective integration into the polymer matrix.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eFigure \u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003e demonstrates the ambient AC conductivity of both pure chitosan and chitosan electrolyte filled with graphite. The conductivity of pure chitosan is 10⁻⁷ S/cm, while chitosan that has been filled with graphite has a conductivity of 10⁻⁴ S/cm. Up to 5 kHz, the conductivity increases linearly. The power law indicates that the sample's AC conductivity is frequency-dependent. \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\sigma\\:}^{ac}={A\\omega\\:}^{\\rho\\:}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\u003cp\u003eA is a constant and ρ is the frequency exponent (where ρ\u0026thinsp;\u0026lt;\u0026thinsp;1) in the expression above. Over a broad frequency range, the ωρ power law is frequently seen in a variety of materials, including polymers.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThe XRD pattern of the TiO₂-CuO admixed nanopowder illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e9\u003c/span\u003e showed sharp, well-defined peaks, confirming the crystalline nature of the material. The absence of any additional peaks indicated that no new phases or compounds were formed during the synthesis, suggesting that both TiO₂ and CuO retained their structural integrity. This crystalline quality is vital for effective electron transport in dye-sensitized solar cells (DSSCs), as it aids in reducing recombination losses and improving overall efficiency. The nanocrystalline structure of the prepared nanomaterial is observe in the SEM image shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e10\u003c/span\u003e. Through the use of SEM and Scherer's equation for the diffraction peaks, the average grain size was determined to be between 20 and 35 nm. The vast amount of dye molecules that can be absorbed by the small grain size will ultimately lead to a high efficiency of the DSSC. It is also evident from the SEM image that CuO is present over the TiO\u003csub\u003e2\u003c/sub\u003e in the form of an island rather than reacting with it to generate a new structure. The increased photoactive area caused by the nanocrystalline nature will raise efficiency of the cell.\u003c/p\u003e\u003cp\u003eThe behaviour of the TiO\u003csub\u003e2\u003c/sub\u003e-CuO photoanode coated with cocktail dye is study via absorption spectra shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig11\" class=\"InternalRef\"\u003e11\u003c/span\u003e. The enhanced interaction between TiO\u003csub\u003e2\u003c/sub\u003e-CuO and cocktail dye is considered to be responsible for the significant increase in the light absorption spectrum, since it facilitates charge transfer and lowers the recombination rate. The capacity of CuO to function as an electron-acceptor amplifies the photocatalytic efficacy of TiO\u003csub\u003e2\u003c/sub\u003e. Furthermore, suitable conduction band of CuO promotes the facile transfer of photogenerated electrons from TiO\u003csub\u003e2\u003c/sub\u003e, hence facilitating effective charge separation.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eFigure \u003cspan refid=\"Fig12\" class=\"InternalRef\"\u003e12\u003c/span\u003e illustrates the FTIR spectra of natural dyes: (a) beetroot, (b) spinach, and (c) cocktail. There are three significant peaks in the spectrum that are linked to beetroot dye: 1028, 1565, and 3248 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. Stretching vibrations in C-O bonds are represented by the peak at 1028 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, whereas stretching vibrations in C-C and O-H bonds are shown by the wider peaks at 1565 and 3248 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, respectively. There are two peaks in the spinach dye spectrum: 1523 cm-1 and 2356 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, representing the characteristic peaks of chlorophyll a (N-H deformation) and chlorophyll b (N-H stretching), respectively. Additionally, a peak appears at 3352 cm-\u003csup\u003e1\u003c/sup\u003e corresponding to the O-H group, as ethanol was used in the extraction process. Prominent peaks associated with C-O and C-H bond stretching is observed at 1742 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 2859 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, respectively. Notably, in the spectrum of the cocktail containing betacyanin and chlorophyll, no suppression effect on either dye is observed, as indicated by the presence of prominent peaks.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eFigure \u003cspan refid=\"Fig13\" class=\"InternalRef\"\u003e13\u003c/span\u003e depicts the light absorption characteristics of betacyanin, chlorophyll, and the cocktail dye coated TiO\u003csub\u003e2\u003c/sub\u003e photoelectrodes. Each dye exhibits distinctive absorption wavelengths attributed to their unique subatomic structures. Betacyanin dye absorbs light primarily in the 550 nm range, while chlorophyll absorbs light around 440 nm. The combination of both dyes results in an enhancement of absorption wavelengths, particularly in the range of about 660 nm. This broader absorption spectrum resulting from the mixing of dyes increases the ability of the dyes to absorb photons from sunlight, leading to the continual regeneration of electrons and, in the end, enhancing performance of the DSSC.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003ephotoelectrodes on ITO glass substrate.\u003c/p\u003e\u003cp\u003eFollowing the characterization of the prepared polymer electrolyte and natural dye, they were employed to assemble the fabricated DSSC, utilizing platinum as the counter electrode. Figure\u0026nbsp;\u003cspan refid=\"Fig14\" class=\"InternalRef\"\u003e14\u003c/span\u003e illustrates a typical J-V curve of the fabricated DSSC. The achieved conversion efficiency was 2.5%, accompanied by a fill factor of 54%. The photocurrent (Isc) was measured at 8.2 mA/cm\u003csup\u003e2\u003c/sup\u003e, while the photovoltage (Voc) was recorded at 0.680 V. In a previous study by Chawla et al. (2018), DSSCs were fabricated using chitosan-based polymer electrolyte with TiO\u003csub\u003e2\u003c/sub\u003e filler and anthocyanin natural dye, resulting in a conversion efficiency of 1.8%. Table\u0026nbsp;1 presents a comparison of the different polymer electrolyte systems based on chitosan that are utilized in DSSCs, along with their conductivity and the efficiency of the fabricated DSSCs.\u003c/p\u003e\u003cp\u003eIn the current work, the incorporation of carbon fillers, namely graphite significantly enhanced the conductivity of the polymer electrolyte system from 10\u003csup\u003e\u0026minus;\u0026thinsp;7\u003c/sup\u003e to 10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e S/cm. This enhancement in conductivity led to an improved efficiency of 2.3%, which is noteworthy in the context of natural dye-sensitized solar cells.\u003c/p\u003e\u003cp\u003e\u003cb\u003eTable \u0026ndash; 1.\u003c/b\u003e Comparation of DSSCs\u0026rsquo; performances utilizing chitosan as host polymer and indifferent fillers.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Taba\" border=\"1\"\u003e\u003ccolgroup cols=\"9\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eS.No\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eElectrolyte system\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eConductivity\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eFF\u003c/p\u003e\u003cp\u003e(Fill Factor)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003ePhotoanode\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003ePhotoc\u0026ndash;athode\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003eDye\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e\u003cp\u003eɳ\u003c/p\u003e\u003cp\u003e(Efficiency)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e1.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eChitosan/TiO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e S/cm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e53%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eTiO\u003csub\u003e2\u003c/sub\u003e-WO\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003ePt\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eNatural dye\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e1.8%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e[21]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eChitosan/LiClO\u003csub\u003e4\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e S/cm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e15%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eZnO\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003ePt\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eOrganic dye (RB)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.05%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e[22]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e3.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eChitosan\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e44.59%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eZnO/ZnS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003ePt\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eN719\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e1.6%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e[23]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e4.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eChitosan/PVDF/HFP\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5.367\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e\u0026nbsp;S/cm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e35%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eTiO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003ePt\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eN719\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e1.23%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e[24]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e5.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eChitosan/Nal\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.11X10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e S/cm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e30%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eTiO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003ePt\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eN719\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.06%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e[25]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e6.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eChitosa/PEO/NH\u003csub\u003e4\u003c/sub\u003eI\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3.66X10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e S/cm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e69%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eTiO\u003csub\u003e2\u003c/sub\u003e/AgNP\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003ePt\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eN3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e1.13%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e[26]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe cell performance of the fabricated DSSCs with a TiO₂-CuO photoelectrode sensitized with a natural cocktail dye is displayed in Fig.\u0026nbsp;\u003cspan refid=\"Fig14\" class=\"InternalRef\"\u003e14\u003c/span\u003e. The efficiency of a DSSC using pure chitosan as a polymer electrolyte was 0.50% and fill factor was 45%, whereas adding graphite filler increased the efficiency to 2.3% and fill factor reported to be 54%.\u003c/p\u003e\u003cp\u003eThe total resistance of pure chitosan electrolyte is elevated due to its crystalline structure, which restricts ionic mobility and the diffusion of iodine/triiodide ions (I\u003csup\u003e\u0026minus;\u003c/sup\u003e/I\u003csub\u003e3\u003c/sub\u003e\u003csup\u003e\u0026minus;\u003c/sup\u003e). The resistance of the pure chitosan-based DSSC is recorded at 712 Ω (Fig.\u0026nbsp;\u003cspan refid=\"Fig15\" class=\"InternalRef\"\u003e15\u003c/span\u003ea). Nevertheless, the use of graphite as a filler into the chitosan-based polymer electrolyte results in a substantial reduction in resistance to 355 Ω (Fig.\u0026nbsp;\u003cspan refid=\"Fig15\" class=\"InternalRef\"\u003e15\u003c/span\u003eb). The decrease in resistance is ascribed to the graphite filler, which interferes with the crystalline domains in the chitosan matrix, so improving its amorphous structure. The augmented amorphous characteristics promote ion transport and elevate ionic conductivity and diffusion coefficients, hence improving DSSC performance.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e(a) Pure Chitosan and (b) Chitosan with graphite as filler\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn this study, we used a chitosan-based polymer electrolyte with graphite filler to fabricate a natural dye-sensitized solar cell (DSSC). According to our research, adding the chitosan polymer electrolyte improved the cell's stability, while adding the graphite filler raised the polymer electrolyte system's conductivity. The photocatalytic effectiveness of the photoanode was enhanced by the addition of CuO to TiO₂. Additionally, higher charge transfer between the dye molecules and the TiO₂-CuO surface was made possible by the cocktail dye's stronger complexation with the surface. Consequently, this dye was able to convert input photons into electrons with greater efficiency.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eConflict interest: \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere are no conflicts to declare. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAuthors are thankful to CSTUP ( Ref. no. CST/ENV/D-668) (council of science \u0026amp;technology, U.P.) for financial support.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor\u0026rsquo;s Contribution\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAuthor Mridula Tripathi proposed an experimental approach, author Priyanka Chawla, Anshu Maurya, Shivansh Tripathi and Kumari Pooja carried out synthesis of samples and their electrochemical study; all authors are participated in preparation of the manuscript and discussion of results.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eDhariwal S (2021). Importance of natural composite dye sensitized solar cell (DSSC) to generate high efficiency and non-toxic energy. \u003cem\u003eAlliance College of Engineering and Design\u003c/em\u003e.\u003c/li\u003e\n \u003cli\u003eGratzel M (2003). 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Performance of polymer electrolyte based on chitosan blended with poly(ethylene oxide) for plasmonic dye-sensitized solar cell. \u003cem\u003eOpt Mater\u003c/em\u003e 57:202\u0026ndash;211. https://doi.org/10.1016/j.optmat.2016.04.028.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"ionics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":" Learn more about [Ionics](https://www.springer.com/journal/11581) ","snPcode":"11581","submissionUrl":"https://mc.manuscriptcentral.com/ionics","title":"Ionics","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Dye Sensitized Solar Cell (DSSC), Chitosan, graphite, fiiler, co-sensitizer and polymer electrolyte","lastPublishedDoi":"10.21203/rs.3.rs-7398761/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7398761/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eA dye-sensitized solar cell (DSSC) consists of four crucial components: a photoanode, electrolyte, sensitizer, and photocathode. The stability, efficiency, and sustainability of a DSSC rely on these components. In this study, a biopolymer (chitosan) with graphite filler has been utilized as the electrolyte system to address sealing and leakage issues associated with liquid electrolytes. Chitosan, with its β(1\u0026ndash;4) linked 2-amino-deoxy-D-glucopyranose units, exhibits a polycationic character that enhances anionic interactions, forming a polyelectrolyte complex. Furthermore, chitosan is biodegradable, eco-friendly, biocompatible, and non-toxic, making it a sustainable choice. The TiO₂ working electrode has been improved with CuO nanopowder to minimize the inherent energy barrier. A cocktail dye, prepared from beetroot and spinach dyes in a 1:1 ratio, is used as the sensitizer, replacing synthetic dyes and enhancing the eco-friendliness of the fabricated DSSC. The reported solar conversion efficiency is approximately 2.3%, with a fill factor of 54%, under an irradiation of 100 mW/cm\u0026sup2;.\u003c/p\u003e","manuscriptTitle":"Enhancement of Solar Cell Performance with Layered Filler Graphite for Natural Dye Sensitized Solar Cell","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-28 18:52:23","doi":"10.21203/rs.3.rs-7398761/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-09-09T14:29:30+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-09T03:45:48+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-30T12:38:57+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"243618038726877147452600361978648557094","date":"2025-08-29T07:40:57+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-28T07:02:21+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"149983220489427884934693563012083845766","date":"2025-08-23T04:05:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"186001514923866008844443957000725083507","date":"2025-08-22T11:01:49+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-08-20T09:03:49+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-08-20T01:46:54+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-08-20T01:46:36+00:00","index":"","fulltext":""},{"type":"submitted","content":"Ionics","date":"2025-08-18T10:36:36+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"ionics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":" Learn more about [Ionics](https://www.springer.com/journal/11581) ","snPcode":"11581","submissionUrl":"https://mc.manuscriptcentral.com/ionics","title":"Ionics","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"0b493bf5-8a03-4738-880a-eb06f5307da7","owner":[],"postedDate":"August 28th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-10-10T08:38:47+00:00","versionOfRecord":[],"versionCreatedAt":"2025-08-28 18:52:23","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7398761","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7398761","identity":"rs-7398761","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}