Current Mechanisms in Zinc Diffusion-doped Silicon Samples at T = 300 K

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U. Arzikulov, M. Radzhabova, S. N. Srajev, N. Mamatkulov, Sh. J. Quvondiqov, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4421869/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract This work is devoted to the study of current flow in diffusion-doped zinc silicon samples in the dark and when illuminated with integral light with an intensity in the range from 0.6 to 140 lx and at a temperature of 300 K. At T = 300 K and in the dark, the view the current-voltage characteristic (CVC) contained all areas characteristic of semiconductors with deep energy levels. It was found that when illuminated with integral light, the type of CVCs of the studied Si samples depended on the value of the applied voltage, the electrical resistivity of the samples, the light intensity, and their number reached up to 6. In this case, linear, sublinear, and superlinear sections were observed, as well as the switching point (sharp current jump) and areas with negative differential conductivities (NDC). The existence of these characteristic areas of the applied voltage and their character depended on the intensity of the integral light. The experimental data obtained were interpreted in connection with the formation of low dimensional objects with the participation of multiply charged zinc nanoclusters in the bulk of silicon. They changed the energy band structure of single-crystal silicon, which affected generation-recombination processes in Si, leading to the types of CVCs observed in the experiment. doped silicon current-voltage characteristic negative differential conductivity low dimensional objects zinc nanoclusters Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 1. Introduction The study of current flow processes in highly compensated (HC) silicon samples doped with zinc in a high non-equilibrium state, at room temperatures and in the presence of integral illumination, is of great scientific and practical interest. From a scientific point of view, such studies provide more information about the role of a particular center formed by impurity atoms on current flow processes. From a practical point of view, knowledge of the behavior of a sample under various conditions makes it possible to determine the optimal conditions for creating various sensors of external influences based on HC silicon samples. It is known that zinc in silicon acts as a double acceptor with ionization energies E 1 = E V +0.31 and E 2 = E V +0.50 eV [ 1 – 3 ]. A study of the surface morphology using an atomic force microscope (AFM) and the photoelectric properties of diffusion zinc-doped silicon samples we synthesized showed that nano-sized multi-charged clusters are formed in them [ 4 ]. These clusters significantly change the structure of the energy states of the zinc atom in silicon. As a result, instead of the above two acceptor energy levels corresponding to a single zinc atom, other deep energy levels appear with the participation of zinc nanoclusters lying in the range of values E = E V +(0.16¸0.617) eV, which is consistent with the data [ 5 ]. 2. Materials and experimental details To elucidate the mechanism of current flows in HC samples of silicon diffusion-doped with zinc with different types of conductivity and degrees of compensation, samples of both n- and p-type conductivities with resistivities lying in the range of 10 2 ÷10 5 Ω∙cm at T = 300 K were fabricated using the method high-temperature diffusion according to the technology described in [ 6 ]. Ohmic contacts to the studied samples were created by laser soldering of copper wire with a diameter of 100 µm or by applying conductive silver glue [ 7 ]. To measure the CVCs of diffusion-doped HC Si samples of both p- and n-types, the setup in [ 8 ] was assembled. Samples of p- or n- n-conductivity types in the form of parallelepipeds with dimensions of 10×5×0.3 mm 3 were included in a circuit consisting of a series-connected load resistance R L and a stabilized voltage source. The voltage generator mode (R S ≫ R L ) was performed regardless of the current flowing through the sample. An incandescent lamp of type SM-9/6, powered by direct current, served as a source of integral lighting. 3. Results and discussion A study of the CVC of HC silicon samples diffusion-doped with zinc of both n- and p- types of conductivity and with electrical resistivities in the range of 10 2 ÷10 5 Ω∙cm at T = 300 K showed that the CVC in the dark contains three characteristic sections (Fig. 1 ). The first section in the dependence \(I={U}^{\alpha }\) is linear (the exponent lies in the range α = 0.97÷1.03) for all studied samples whose length in voltage increases approximately 10 times with increasing ρ (for example, 0.1 ÷ 10 V for a sample with ρ = 1.3∙10 2 Ω∙cm and 0.1÷100 V for a sample with ρ = 6.91∙10 4 Ω∙cm). The second section is superlinear (the exponent is equal to the value 1.28¸1.97). The third section of the CVC is a section of a sharp increase in current from voltage. Here the value reaches up to 25.03. At first glance, the last section looks like an electrical breakdown. However, repeated measurements have shown that the experimental data is repeatable; therefore, we can say there is no electrical breakdown here. It should be noted that the exponent increases sharply in this section with increases of the ρ. Figure 2 shows the CVCs of n–Si samples, also taken at room temperature and in the presence of integral illumination with an intensity of 0.6–90 lx. As can be seen from Fig. 2 the CVCs of n–Si samples taken at low illumination of integral light have three characteristic sections [ 9 ]. The first almost linear section with the index α = 0.99 lies in the voltage range 0.10 ÷ 9 V, then follows the superlinear section with α = 1.24 lying in the voltage range 10 ÷ 90 V, then follows the sublinear section with the index α = 0.554 lying in the range 100 ÷ 950 V [ 10 ]. As the light irradiance value (LIV) increases, the number of characteristic areas and the nature of the \(I={U}^{\alpha }\) dependence changes. So, for example, at 6.25 lx the number of characteristic areas reaches six and this number is maintained for all LIV. In this case, the voltage extension of the first ohmic section is preserved for all values of the LIV. The nature of the second section does not change, i.e. it's always super linear. However, the degree of superlinearity increases from the beginning, and having reached a maximum ( α = 1.77), it decreases ( α = 1.55). The third section at low LIV is sublinear ( α = 0.68) and with increasing LIV the sublinearity decreases ( α = 0.75) with further growth of LIV it first turns into a linear dependence ( α = 0.97) and then becomes superlinear ( α = 1.15). The fourth section at relatively low LIV (6.25-23 lx) exhibits a superlinear dependence ( α = 1.44¸2.04), then, as in the third section, it first turns almost linear ( α = 1.08), and then a weak sublinear relationship ( α = 0.90). The fifth section is a section of a sharp jump in current downward in value. The threshold voltage corresponding to a current surge depends on the LIV. At low LIV, the jump occurs at higher values of voltage applied to the sample. With increasing LIV, the current sharply decreases, and, starting from 23 lx, the current jump does not depend on the LIV (Fig. 3 ), but the magnitude of its jump (ΔΙ = I max – I min ) depends on the LIV. At low LIV, the value of ΔΙ is small and with increasing LIV it increases sharply, and, starting from LIV 23 lx, its growth slows down (Fig. 4 ). Figure 5 shows the CVCs of HC samples p–Si with ρ = 6.91 ∙10 4 Ω∙cm taken at a temperature T = 300 K in the presence of integral illumination with an intensity lying in the range of 0.6 ÷ 100 lx. As can be seen from Fig. 5 , in contrast to n–Si samples, the I–V characteristics of p–Si taken at T = 300 K and low LIV contain 6 characteristic sections (instead of three). These are sections: the first almost linear section with the indicator α = 0.98 lies in the voltage range 0.10 ÷ 9 V, and this dependence is preserved for all LIV, then follows the second superlinear section with α = 1.73¸2.08, lying in the voltage range 10 ÷ 30 V, followed by the third sublinear section with the index α = 0.42, lying in the range 40 ÷ 100 V. With an increase in the LIV, this section moves to a superlinear dependence with the index α , lying in the range 1.27¸1,45. Next comes the fourth superlinear section with α = 2.55. With increasing LIV, this dependence becomes sublinear, and the value decreases. The fifth is a section of a sharp jump in current downward in value. The voltage corresponding to the current surge depends on the LIV. At low values of the LIV, the jump occurs at higher values of the voltage applied to the sample. With increasing LIV, the threshold voltage value decreases sharply, and starting from 23 Lx, as in the case of p–Si samples, it ceases to be affected by the LIV (Fig. 3 ). In this case, the magnitude of the jump (ΔΙ = I max – I min ) also depends on the LIV. At low LIV, the value of ΔΙ is small, but with increasing LIV it increases sharply and, starting from LIV 23 lx, its growth slows down (Fig. 4 ). It should be noted that in n–Si both the value of the threshold voltage U th and the value of ΔΙ are always greater than in p–Si . The nonlinearity of the CVC occurs not only in many semiconductor devices, in which the main working element is p-n junctions but also in many semiconductor materials in which p-n junctions are completely absent [ 11 ]. In semiconductor materials, if we exclude the influence of contacts, nonlinearity is most often due to the effects of strong fields. It is known that in strong electric fields, there is a dependence of mobility on the field strength until velocity saturation, NDC, impact ionization, and breakdown. However, in weak electric fields, the manifestation of nonlinearity of the CVC is also possible [ 12 ]. In [ 6 ], it was shown that in the silicon samples we studied, diffusion-doped with zinc at low voltages, the dependence of the current flowing through the sample on the applied voltage is linear. At higher voltages, nonlinearities appear in the I-V dependence, which is described by the theory of limited space charge current (SCLC) by trapping holes at levels created by zinc atoms located in the band gap of silicon [ 13 ]. However, the exact reasons for the nonlinear nature of the CVCs in semiconductors have not yet been unambiguously established [ 14 ]. According to [ 15 ], the nonlinearity of the relationship between excess carrier concentrations in compensated semiconductors leads to a complex dependence on the parameters that determine the shape of the CVCs on the injection level. An important role in the formation of the CVCs of the diode structure is played by the bipolar drift mobility and the effective diffusion coefficient. In the expressions that determine the above quantities, there is a function ν(p) = dn/dp, the form of which is determined by the specific type of the system of deep impurity levels in the compensated semiconductor. At low and high injection levels, when carrier concentrations are related by a linear dependence and the value of ν(p) is constant, the influence of equilibrium parameters on the values of mobility and diffusion coefficient has a weak effect. When considering the mechanisms responsible for the behavior of the CVCs of a compensated semiconductor, it is necessary to take into account the influence of simultaneous changes in the bipolar drift mobility and the effective diffusion coefficient, which is a difficult task in practice. In our case, possible reasons for the nonlinearity of the CVCs in Si samples may be the following mechanisms: i) currents limited by space charges; ii) and ionization of impurity centers in strong electric fields [ 14 , 16 ]. As was shown in [ 14 ], when a voltage is applied to samples with high resistance, an injection current appears in the circuit, which obeys the power law J ∼ E 2 . The nonlinear sections of the CVCs in such samples containing shallow and deep traps were mainly associated with the possibility of implementing monopolar or double injection. In the HC Si samples we studied, there are r− (slow, associated with doubly ionized zinc atoms) and s− (fast, levels arising during high-temperature diffusion) recombination centers, as well as t– trap levels associated with shallow levels [ 17 ]. This suggests that in fields where a quadratic dependence J ∼ E 2 is observed, the CVC exhibits a trap character of conductivity. The experimental data obtained in the corresponding sections of the CVC show that in p- and n-type Si samples, the transport of charge carriers in electric fields with a strength of less than 10 2 V/cm is mainly due to monopolar injection and is consistent with Lampert’s theory [ 9 ]. The sections of the CVC with α < 1 that we studied for p- and n-type Si samples can be satisfactorily explained within the framework of the theory of the “injection depletion effect” [ 13 ]. The appearance of sublinear sections of the CVC is theoretically possible only in the case of counter-directions of ambipolar diffusion of nonequilibrium current carriers and their ambipolar drift, which in our case is mainly determined by injection modulation of the charge of deep levels [ 18 ]. Due to the difference in diffusion coefficients, holes move slowly, and electrons run far ahead, which leads to their separation in space and an electric field arises between them, inhibiting their movement. A decrease in their speed causes a decrease in current, which in turn leads to the appearance of sublinear sections of the CVC. Analysis of the results of experimental data obtained at relatively high electric field strengths (at E > 10 2 V/cm) shows that the increase in electrical conductivity with increasing E is associated with an increase in the concentration of excess charge carriers. This circumstance allows us to assume that the presence of a region of the sharper current growth in the CVC, where α > 3, can be explained by the fact that in Si p– and n-type samples at such E, depletion (or ionization) occurs traps stimulated by an electric field. There is another mechanism that also leads to a strong change in the concentration of charge carriers. This may be due to a sharp increase in the degree of ionization of small donors or acceptors when free carriers are heated by an electric field. Such a sharp increase in the degree of ionization can be associated both with an increase in the rate of impact ionization upon heating of charge carriers and with the field dependence of the probability of their capture by similarly charged traps. This is only possible at very low temperatures. In fields of the order of 10 2 V/cm, almost complete release of charge carriers from traps occurs, which leads to sharp superlinearity of the CVC. At present, however, there is still no complete clarity regarding the specific mechanism of origin of the region responsible for NDC [ 10 ]. The origin of the fifth region, where a downward current jump is observed at certain values of voltage applied to the sample, is not yet completely clear. Such a current jump may be associated with the “opening” of a new additional recombination channel associated with zinc atoms. In this case, the capture cross section for nonequilibrium charge carriers at the center corresponding to this channel probably depends on the electric field strength. When the threshold voltage value is reached, this channel “opens”, which leads to a sharp decrease in the number of current carriers and corresponds to a current jump down in value. In [ 19 ], a model of a semiconductor with quantum dots (QDs) was used to explain the experimental data obtained. It is known that the presence in the band gap of a semiconductor of various traps for charge carriers associated with impurity atoms significantly affects the type of their CVCs. This is especially evident in HC semiconductor materials. In this case, instead of a linear section, followed by quadratic and almost vertical dependencies, S - or N -shaped sections also appear on the CVC. I-V characteristics with several NDCs or the simultaneous presence of S - and N -shaped characteristics are also possible [ 10 ]. The results obtained can be interpreted in such a way that zinc atoms in silicon, with strong compensation, form not only single deep levels but also an entire band of levels characteristic of nanoclusters (or quantum dots) with large carrier capture cross sections [ 7 ]. The value of the electrical resistivity of Si samples of both n- and p-type conductivity with NC with different charge states, obtained by high-temperature diffusion lies in a wide range (ρ ~ 10 2 ÷10 4 Ω∙cm), i.e. they are quite high-resistance. These NCs are deep traps for charge carriers. Unlike conventional traps, where carriers are at a fixed energy level, in NC they are not only bound but can also be at different quantized energy levels with different densities of states and capture cross sections. The nature of their distribution among levels depends on the degree of compensation, on injection, etc., in addition, the process of tunneling between NCs is possible. Therefore, it should be expected that the CVCs in such materials should have their characteristics, which were experimentally discovered in the Si samples with NC we studied [ 20 ]. It should also be noted that with a decrease in the resistivity of the samples, the value of the vertical section of the CVC also decreases. Knowing the charge carrier concentrations at a given temperature, we calculated the positions of the Fermi level in these samples at T = 300 K, which are F 1 = 0.35 eV, F 2 = 0.43 eV, and F 3 = 0.49 eV, respectively. Therefore, it can be assumed that in these samples the NCs act as traps with different concentrations and ionization energies, which are higher than the Fermi level. Let's consider that in the samples under study there are only NCs with different charge multiplicities. We can assume that the detected energy levels correspond to their different charge states. 4. Conclusions Based on the studies of the electrical properties of silicon samples diffusion-doped with zinc, it was established that the CVC consists of several characteristic sections (the number of which can reach up to 6): linear, sublinear, superlinear, switching point, and section with NDC. Their number and voltage ranges depend on the temperature, degree of illumination, and resistivity of the sample. The sublinear sections of the CVC observed in p- and n-type Si samples can be satisfactorily explained within the framework of the theory of the injection depletion effect. The observed quadratic dependences J ∼ E 2 in the CVC can be associated with the influence of traps on conductivity. In the p- and n-type Si samples we studied, the transfer of charge carriers in electric fields with a strength of less than 10 2 V/cm is mainly due to monopolar injection and is consistent with Lampert’s theory. The presence of a region of sharper current growth in the CVC, where α > 3, can be explained by the fact that in Si p- and n-type samples at such electric field strengths, emptying (or ionization) of traps occurs, stimulated by the electric field. The observed features in the CVC are mainly associated with the formation of nano-sized multiply charged clusters, which significantly change the structure of the energy states of zinc atoms in silicon. As a result, instead of the well-known two acceptor energy levels corresponding to atomic zinc, a whole spectrum of deep donor energy levels of zinc nanoclusters appears lying in the range E = E V +(0.16 ÷ 0.4) eV. Declarations Declarations Ethical Approval Not applicable. Competing Interests The authors declare no competing interests. Author Contribution E.A., S.S., and V.P. conceived and planned the experiments. M.R., N.M., and S.Q. carried out the experiments. S.S., and M.R. contributed to sample preparation. E.A., and B.Y. contributed to the interpretation of the results. E.A. took the lead in writing the manuscript. All authors provided critical feedback and helped shape the research, analysis, and manuscript. Acknowledgement This study was supported by the Open Fund of Hubei Key Laboratory of Electronic Manufacturing and Packaging Integration (Wuhan University) (Grant No. EMPI2024017). Data Availability No datasets were generated or analyzed during the current study. Code Availability Not Applicable. 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Technosphere, Moscow Rafiq MA (2018) J Semicond. 39: 061002-1-061002-13. 10.1088/1674-4926/39/6/061002 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-4421869","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":317685073,"identity":"949ac2b6-f0d0-42fb-848e-efe00d124187","order_by":0,"name":"E. U. 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Srajev","email":"","orcid":"","institution":"Samarkand State University","correspondingAuthor":false,"prefix":"","firstName":"S.","middleName":"N.","lastName":"Srajev","suffix":""},{"id":317685076,"identity":"d79cb7f7-7a6a-48ec-83cd-8e677315b109","order_by":3,"name":"N. Mamatkulov","email":"","orcid":"","institution":"Samarkand State University Veterinary Medicine, Livestock and Biotechnologies","correspondingAuthor":false,"prefix":"","firstName":"N.","middleName":"","lastName":"Mamatkulov","suffix":""},{"id":317685077,"identity":"08aeef5d-aebf-4365-b3d7-662921a6b1b6","order_by":4,"name":"Sh. J. Quvondiqov","email":"","orcid":"","institution":"Samarkand State University","correspondingAuthor":false,"prefix":"","firstName":"Sh.","middleName":"J.","lastName":"Quvondiqov","suffix":""},{"id":317685078,"identity":"d0d0349f-a08f-4cfb-ab79-cbc3c40a2b6c","order_by":5,"name":"Vasiliy O. Pelenovich","email":"","orcid":"","institution":"Wuhan University","correspondingAuthor":false,"prefix":"","firstName":"Vasiliy","middleName":"O.","lastName":"Pelenovich","suffix":""},{"id":317685079,"identity":"a3a5ccb5-9c9d-46e2-9b6a-e754d44520c7","order_by":6,"name":"Bing Yang","email":"","orcid":"","institution":"Wuhan University","correspondingAuthor":false,"prefix":"","firstName":"Bing","middleName":"","lastName":"Yang","suffix":""}],"badges":[],"createdAt":"2024-05-15 01:38:15","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4421869/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4421869/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":59219106,"identity":"efa6720b-1009-4733-9f14-6de7320da1e0","added_by":"auto","created_at":"2024-06-27 19:57:08","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":15093,"visible":true,"origin":"","legend":"\u003cp\u003eCVCs of Si\u0026lt;P, Zn\u0026gt; samples with different specific electrical resistances and types of conductivity in the dark at T = 300 K\u003c/p\u003e","description":"","filename":"image1.png","url":"https://assets-eu.researchsquare.com/files/rs-4421869/v1/cc06d21602ac964d9850f104.png"},{"id":59219107,"identity":"97a74e64-7aa1-40c3-8a1a-5110b3689ae4","added_by":"auto","created_at":"2024-06-27 19:57:08","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":16227,"visible":true,"origin":"","legend":"\u003cp\u003eCVCs of n–Si\u0026lt;P, Zn\u0026gt; samples with ρ = 5.74 ∙10\u003csup\u003e4\u003c/sup\u003e Ω∙cm, T = 300 K\u003c/p\u003e","description":"","filename":"image2.png","url":"https://assets-eu.researchsquare.com/files/rs-4421869/v1/e8b6f37445cd962146e99a94.png"},{"id":59219108,"identity":"f40e9ff5-257c-4916-b9ca-bdd1a512308f","added_by":"auto","created_at":"2024-06-27 19:57:08","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":11016,"visible":true,"origin":"","legend":"\u003cp\u003eDependence of the threshold voltage of the current jump on the illumination of the integral light\u003c/p\u003e","description":"","filename":"image3.png","url":"https://assets-eu.researchsquare.com/files/rs-4421869/v1/c956d7d81eee02c699468743.png"},{"id":59219109,"identity":"7313acbb-3d8a-4097-b19d-52ff9a617095","added_by":"auto","created_at":"2024-06-27 19:57:08","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":11438,"visible":true,"origin":"","legend":"\u003cp\u003eDependence of the magnitude of the current jump on the illumination of the integral light\u003c/p\u003e","description":"","filename":"image4.png","url":"https://assets-eu.researchsquare.com/files/rs-4421869/v1/b1a99603e34055edbfe72ef1.png"},{"id":59219110,"identity":"e6c51faf-112d-4f7d-b158-8b5b65c220d5","added_by":"auto","created_at":"2024-06-27 19:57:08","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":13862,"visible":true,"origin":"","legend":"\u003cp\u003eCVCs of n–Si\u0026lt;P,Zn\u0026gt; samples with ρ = 6.91 ∙10\u003csup\u003e4\u003c/sup\u003e Ω∙cm, T = 300 K\u003c/p\u003e","description":"","filename":"image5.png","url":"https://assets-eu.researchsquare.com/files/rs-4421869/v1/0c7fa91d19f7986e0b7aec6c.png"},{"id":60048985,"identity":"d609b07b-d392-4cce-9732-1d77207290e2","added_by":"auto","created_at":"2024-07-11 05:36:23","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":360203,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4421869/v1/68ea8d12-7d37-43bc-924a-98bd391e56c5.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Current Mechanisms in Zinc Diffusion-doped Silicon Samples at T = 300 K","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eThe study of current flow processes in highly compensated (HC) silicon samples doped with zinc in a high non-equilibrium state, at room temperatures and in the presence of integral illumination, is of great scientific and practical interest. From a scientific point of view, such studies provide more information about the role of a particular center formed by impurity atoms on current flow processes. From a practical point of view, knowledge of the behavior of a sample under various conditions makes it possible to determine the optimal conditions for creating various sensors of external influences based on HC silicon samples.\u003c/p\u003e \u003cp\u003eIt is known that zinc in silicon acts as a double acceptor with ionization energies E\u003csub\u003e1\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;E\u003csub\u003eV\u003c/sub\u003e+0.31 and E\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;E\u003csub\u003eV\u003c/sub\u003e+0.50 eV [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. A study of the surface morphology using an atomic force microscope (AFM) and the photoelectric properties of diffusion zinc-doped silicon samples we synthesized showed that nano-sized multi-charged clusters are formed in them [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. These clusters significantly change the structure of the energy states of the zinc atom in silicon. As a result, instead of the above two acceptor energy levels corresponding to a single zinc atom, other deep energy levels appear with the participation of zinc nanoclusters lying in the range of values E\u0026thinsp;=\u0026thinsp;E\u003csub\u003eV\u003c/sub\u003e+(0.16\u0026cedil;0.617) eV, which is consistent with the data [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e"},{"header":"2. Materials and experimental details","content":"\u003cp\u003eTo elucidate the mechanism of current flows in HC samples of silicon diffusion-doped with zinc with different types of conductivity and degrees of compensation, samples of both n- and p-type conductivities with resistivities lying in the range of 10\u003csup\u003e2\u003c/sup\u003e\u0026divide;10\u003csup\u003e5\u003c/sup\u003e Ω∙cm at T\u0026thinsp;=\u0026thinsp;300 K were fabricated using the method high-temperature diffusion according to the technology described in [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Ohmic contacts to the studied samples were created by laser soldering of copper wire with a diameter of 100 \u0026micro;m or by applying conductive silver glue [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTo measure the CVCs of diffusion-doped HC Si\u0026thinsp;\u0026lt;\u0026thinsp;P, Zn\u0026thinsp;\u0026gt;\u0026thinsp;samples of both p- and n-types, the setup in [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] was assembled. Samples of p- or n- n-conductivity types in the form of parallelepipeds with dimensions of 10\u0026times;5\u0026times;0.3 mm\u003csup\u003e3\u003c/sup\u003e were included in a circuit consisting of a series-connected load resistance R\u003csub\u003eL\u003c/sub\u003e and a stabilized voltage source. The voltage generator mode (R\u003csub\u003eS\u003c/sub\u003e ≫ R\u003csub\u003eL\u003c/sub\u003e) was performed regardless of the current flowing through the sample. An incandescent lamp of type SM-9/6, powered by direct current, served as a source of integral lighting.\u003c/p\u003e"},{"header":"3. Results and discussion","content":"\u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eA study of the CVC of HC silicon samples diffusion-doped with zinc of both n- and p- types of conductivity and with electrical resistivities in the range of 10\u003csup\u003e2\u003c/sup\u003e\u0026divide;10\u003csup\u003e5\u003c/sup\u003e Ω∙cm at T\u0026thinsp;=\u0026thinsp;300 K showed that the CVC in the dark contains three characteristic sections (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eThe first section in the dependence \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(I={U}^{\\alpha }\\)\u003c/span\u003e\u003c/span\u003e is linear (the exponent lies in the range \u003cem\u003eα\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.97\u0026divide;1.03) for all studied samples whose length in voltage increases approximately 10 times with increasing ρ (for example, 0.1 \u0026divide;\u0026thinsp;10 V for a sample with ρ\u0026thinsp;=\u0026thinsp;1.3∙10\u003csup\u003e2\u003c/sup\u003e Ω∙cm and 0.1\u0026divide;100 V for a sample with ρ\u0026thinsp;=\u0026thinsp;6.91∙10\u003csup\u003e4\u003c/sup\u003e Ω∙cm). The second section is superlinear (the exponent is equal to the value 1.28\u0026cedil;1.97). The third section of the CVC is a section of a sharp increase in current from voltage. Here the value reaches up to 25.03. At first glance, the last section looks like an electrical breakdown. However, repeated measurements have shown that the experimental data is repeatable; therefore, we can say there is no electrical breakdown here. It should be noted that the exponent increases sharply in this section with increases of the ρ.\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003cp\u003eFigure\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows the CVCs of n\u0026ndash;Si\u0026thinsp;\u0026lt;\u0026thinsp;P, Zn\u0026thinsp;\u0026gt;\u0026thinsp;samples, also taken at room temperature and in the presence of integral illumination with an intensity of 0.6\u0026ndash;90 lx.\u003c/p\u003e \u003cp\u003eAs can be seen from Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e the CVCs of n\u0026ndash;Si\u0026thinsp;\u0026lt;\u0026thinsp;P, Zn\u0026thinsp;\u0026gt;\u0026thinsp;samples taken at low illumination of integral light have three characteristic sections [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. The first almost linear section with the index \u003cem\u003eα\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.99 lies in the voltage range 0.10\u0026thinsp;\u0026divide;\u0026thinsp;9 V, then follows the superlinear section with \u003cem\u003eα\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.24 lying in the voltage range 10\u0026thinsp;\u0026divide;\u0026thinsp;90 V, then follows the sublinear section with the index \u003cem\u003eα\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.554 lying in the range 100\u0026thinsp;\u0026divide;\u0026thinsp;950 V [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. As the light irradiance value (LIV) increases, the number of characteristic areas and the nature of the \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(I={U}^{\\alpha }\\)\u003c/span\u003e\u003c/span\u003e dependence changes. So, for example, at 6.25 lx the number of characteristic areas reaches six and this number is maintained for all LIV. In this case, the voltage extension of the first ohmic section is preserved for all values of the LIV. The nature of the second section does not change, i.e. it's always super linear. However, the degree of superlinearity increases from the beginning, and having reached a maximum (\u003cem\u003eα\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.77), it decreases (\u003cem\u003eα\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.55). The third section at low LIV is sublinear (\u003cem\u003eα\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.68) and with increasing LIV the sublinearity decreases (\u003cem\u003eα\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.75) with further growth of LIV it first turns into a linear dependence (\u003cem\u003eα\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.97) and then becomes superlinear (\u003cem\u003eα\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.15). The fourth section at relatively low LIV (6.25-23 lx) exhibits a superlinear dependence (\u003cem\u003eα\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.44\u0026cedil;2.04), then, as in the third section, it first turns almost linear (\u003cem\u003eα\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.08), and then a weak sublinear relationship (\u003cem\u003eα\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.90). The fifth section is a section of a sharp jump in current downward in value. The threshold voltage corresponding to a current surge depends on the LIV. At low LIV, the jump occurs at higher values of voltage applied to the sample. With increasing LIV, the current sharply decreases, and, starting from 23 lx, the current jump does not depend on the LIV (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e), but the magnitude of its jump (ΔΙ\u0026thinsp;=\u0026thinsp;I\u003csub\u003emax\u003c/sub\u003e \u0026ndash; I\u003csub\u003emin\u003c/sub\u003e) depends on the LIV. At low LIV, the value of ΔΙ is small and with increasing LIV it increases sharply, and, starting from LIV 23 lx, its growth slows down (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e shows the CVCs of HC samples p\u0026ndash;Si\u0026thinsp;\u0026lt;\u0026thinsp;P, Zn\u0026thinsp;\u0026gt;\u0026thinsp;with ρ\u0026thinsp;=\u0026thinsp;6.91 ∙10\u003csup\u003e4\u003c/sup\u003e Ω∙cm taken at a temperature T\u0026thinsp;=\u0026thinsp;300 K in the presence of integral illumination with an intensity lying in the range of 0.6\u0026thinsp;\u0026divide;\u0026thinsp;100 lx.\u003c/p\u003e \u003cp\u003eAs can be seen from Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e, in contrast to n\u0026ndash;Si\u0026thinsp;\u0026lt;\u0026thinsp;P, Zn\u0026thinsp;\u0026gt;\u0026thinsp;samples, the I\u0026ndash;V characteristics of p\u0026ndash;Si\u0026thinsp;\u0026lt;\u0026thinsp;P, Zn\u0026thinsp;\u0026gt;\u0026thinsp;taken at T\u0026thinsp;=\u0026thinsp;300 K and low LIV contain 6 characteristic sections (instead of three). These are sections: the first almost linear section with the indicator \u003cem\u003eα\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.98 lies in the voltage range 0.10\u0026thinsp;\u0026divide;\u0026thinsp;9 V, and this dependence is preserved for all LIV, then follows the second superlinear section with \u003cem\u003eα\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.73\u0026cedil;2.08, lying in the voltage range 10\u0026thinsp;\u0026divide;\u0026thinsp;30 V, followed by the third sublinear section with the index \u003cem\u003eα\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.42, lying in the range 40\u0026thinsp;\u0026divide;\u0026thinsp;100 V. With an increase in the LIV, this section moves to a superlinear dependence with the index\u003cem\u003eα\u003c/em\u003e, lying in the range 1.27\u0026cedil;1,45. Next comes the fourth superlinear section with \u003cem\u003eα\u003c/em\u003e\u0026thinsp;=\u0026thinsp;2.55. With increasing LIV, this dependence becomes sublinear, and the value decreases. The fifth is a section of a sharp jump in current downward in value. The voltage corresponding to the current surge depends on the LIV. At low values of the LIV, the jump occurs at higher values of the voltage applied to the sample. With increasing LIV, the threshold voltage value decreases sharply, and starting from 23 Lx, as in the case of p\u0026ndash;Si\u0026thinsp;\u0026lt;\u0026thinsp;P, Zn\u0026thinsp;\u0026gt;\u0026thinsp;samples, it ceases to be affected by the LIV (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). In this case, the magnitude of the jump (ΔΙ\u0026thinsp;=\u0026thinsp;I\u003csub\u003emax\u003c/sub\u003e \u0026ndash; I\u003csub\u003emin\u003c/sub\u003e) also depends on the LIV. At low LIV, the value of ΔΙ is small, but with increasing LIV it increases sharply and, starting from LIV 23 lx, its growth slows down (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). It should be noted that in n\u0026ndash;Si\u0026thinsp;\u0026lt;\u0026thinsp;P, Zn\u0026thinsp;\u0026gt;\u0026thinsp;both the value of the threshold voltage U\u003csub\u003eth\u003c/sub\u003e and the value of ΔΙ are always greater than in p\u0026ndash;Si\u0026thinsp;\u0026lt;\u0026thinsp;P, Zn\u0026gt;.\u003c/p\u003e \u003cp\u003eThe nonlinearity of the CVC occurs not only in many semiconductor devices, in which the main working element is \u003cem\u003ep-n\u003c/em\u003e junctions but also in many semiconductor materials in which \u003cem\u003ep-n\u003c/em\u003e junctions are completely absent [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. In semiconductor materials, if we exclude the influence of contacts, nonlinearity is most often due to the effects of strong fields. It is known that in strong electric fields, there is a dependence of mobility on the field strength until velocity saturation, NDC, impact ionization, and breakdown. However, in weak electric fields, the manifestation of nonlinearity of the CVC is also possible [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eIn [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], it was shown that in the silicon samples we studied, diffusion-doped with zinc at low voltages, the dependence of the current flowing through the sample on the applied voltage is linear. At higher voltages, nonlinearities appear in the \u003cem\u003eI-V\u003c/em\u003e dependence, which is described by the theory of limited space charge current (SCLC) by trapping holes at levels created by zinc atoms located in the band gap of silicon [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eHowever, the exact reasons for the nonlinear nature of the CVCs in semiconductors have not yet been unambiguously established [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. According to [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e], the nonlinearity of the relationship between excess carrier concentrations in compensated semiconductors leads to a complex dependence on the parameters that determine the shape of the CVCs on the injection level. An important role in the formation of the CVCs of the diode structure is played by the bipolar drift mobility and the effective diffusion coefficient. In the expressions that determine the above quantities, there is a function ν(p)\u0026thinsp;=\u0026thinsp;dn/dp, the form of which is determined by the specific type of the system of deep impurity levels in the compensated semiconductor. At low and high injection levels, when carrier concentrations are related by a linear dependence and the value of ν(p) is constant, the influence of equilibrium parameters on the values of mobility and diffusion coefficient has a weak effect. When considering the mechanisms responsible for the behavior of the CVCs of a compensated semiconductor, it is necessary to take into account the influence of simultaneous changes in the bipolar drift mobility and the effective diffusion coefficient, which is a difficult task in practice.\u003c/p\u003e \u003cp\u003eIn our case, possible reasons for the nonlinearity of the CVCs in Si\u0026thinsp;\u0026lt;\u0026thinsp;P, Zn\u0026thinsp;\u0026gt;\u0026thinsp;samples may be the following mechanisms: i) currents limited by space charges; ii) and ionization of impurity centers in strong electric fields [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. As was shown in [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], when a voltage is applied to samples with high resistance, an injection current appears in the circuit, which obeys the power law \u003cem\u003eJ \u0026sim; E\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e. The nonlinear sections of the CVCs in such samples containing shallow and deep traps were mainly associated with the possibility of implementing monopolar or double injection.\u003c/p\u003e \u003cp\u003eIn the HC Si\u0026thinsp;\u0026lt;\u0026thinsp;P, Zn\u0026thinsp;\u0026gt;\u0026thinsp;samples we studied, there are r\u0026minus; (slow, associated with doubly ionized zinc atoms) and s\u0026minus; (fast, levels arising during high-temperature diffusion) recombination centers, as well as t\u0026ndash; trap levels associated with shallow levels [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. This suggests that in fields where a quadratic dependence \u003cem\u003eJ \u0026sim; E\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e is observed, the CVC exhibits a trap character of conductivity. The experimental data obtained in the corresponding sections of the CVC show that in p- and n-type Si\u0026thinsp;\u0026lt;\u0026thinsp;P, Zn\u0026thinsp;\u0026gt;\u0026thinsp;samples, the transport of charge carriers in electric fields with a strength of less than 10\u003csup\u003e2\u003c/sup\u003e V/cm is mainly due to monopolar injection and is consistent with Lampert\u0026rsquo;s theory [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe sections of the CVC with \u003cem\u003eα\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;1 that we studied for p- and n-type Si\u0026thinsp;\u0026lt;\u0026thinsp;P, Zn\u0026thinsp;\u0026gt;\u0026thinsp;samples can be satisfactorily explained within the framework of the theory of the \u0026ldquo;injection depletion effect\u0026rdquo; [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. The appearance of sublinear sections of the CVC is theoretically possible only in the case of counter-directions of ambipolar diffusion of nonequilibrium current carriers and their ambipolar drift, which in our case is mainly determined by injection modulation of the charge of deep levels [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Due to the difference in diffusion coefficients, holes move slowly, and electrons run far ahead, which leads to their separation in space and an electric field arises between them, inhibiting their movement. A decrease in their speed causes a decrease in current, which in turn leads to the appearance of sublinear sections of the CVC.\u003c/p\u003e \u003cp\u003eAnalysis of the results of experimental data obtained at relatively high electric field strengths (at E\u0026thinsp;\u0026gt;\u0026thinsp;10\u003csup\u003e2\u003c/sup\u003e V/cm) shows that the increase in electrical conductivity with increasing E is associated with an increase in the concentration of excess charge carriers. This circumstance allows us to assume that the presence of a region of the sharper current growth in the CVC, where \u003cem\u003eα\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;3, can be explained by the fact that in Si\u0026thinsp;\u0026lt;\u0026thinsp;P, Zn\u0026thinsp;\u0026gt;\u0026thinsp;p\u0026ndash; and n-type samples at such E, depletion (or ionization) occurs traps stimulated by an electric field.\u003c/p\u003e \u003cp\u003eThere is another mechanism that also leads to a strong change in the concentration of charge carriers. This may be due to a sharp increase in the degree of ionization of small donors or acceptors when free carriers are heated by an electric field. Such a sharp increase in the degree of ionization can be associated both with an increase in the rate of impact ionization upon heating of charge carriers and with the field dependence of the probability of their capture by similarly charged traps. This is only possible at very low temperatures. In fields of the order of 10\u003csup\u003e2\u003c/sup\u003e V/cm, almost complete release of charge carriers from traps occurs, which leads to sharp superlinearity of the CVC. At present, however, there is still no complete clarity regarding the specific mechanism of origin of the region responsible for NDC [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe origin of the fifth region, where a downward current jump is observed at certain values of voltage applied to the sample, is not yet completely clear. Such a current jump may be associated with the \u0026ldquo;opening\u0026rdquo; of a new additional recombination channel associated with zinc atoms. In this case, the capture cross section for nonequilibrium charge carriers at the center corresponding to this channel probably depends on the electric field strength. When the threshold voltage value is reached, this channel \u0026ldquo;opens\u0026rdquo;, which leads to a sharp decrease in the number of current carriers and corresponds to a current jump down in value.\u003c/p\u003e \u003cp\u003eIn [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], a model of a semiconductor with quantum dots (QDs) was used to explain the experimental data obtained. It is known that the presence in the band gap of a semiconductor of various traps for charge carriers associated with impurity atoms significantly affects the type of their CVCs. This is especially evident in HC semiconductor materials. In this case, instead of a linear section, followed by quadratic and almost vertical dependencies, \u003cem\u003eS\u003c/em\u003e- or \u003cem\u003eN\u003c/em\u003e-shaped sections also appear on the CVC. \u003cem\u003eI-V\u003c/em\u003e characteristics with several NDCs or the simultaneous presence of \u003cem\u003eS\u003c/em\u003e- and \u003cem\u003eN\u003c/em\u003e-shaped characteristics are also possible [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe results obtained can be interpreted in such a way that zinc atoms in silicon, with strong compensation, form not only single deep levels but also an entire band of levels characteristic of nanoclusters (or quantum dots) with large carrier capture cross sections [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe value of the electrical resistivity of Si\u0026thinsp;\u0026lt;\u0026thinsp;P, Zn\u0026thinsp;\u0026gt;\u0026thinsp;samples of both n- and p-type conductivity with NC with different charge states, obtained by high-temperature diffusion lies in a wide range (ρ\u0026thinsp;~\u0026thinsp;10\u003csup\u003e2\u003c/sup\u003e\u0026divide;10\u003csup\u003e4\u003c/sup\u003e Ω∙cm), i.e. they are quite high-resistance. These NCs are deep traps for charge carriers. Unlike conventional traps, where carriers are at a fixed energy level, in NC they are not only bound but can also be at different quantized energy levels with different densities of states and capture cross sections. The nature of their distribution among levels depends on the degree of compensation, on injection, etc., in addition, the process of tunneling between NCs is possible. Therefore, it should be expected that the CVCs in such materials should have their characteristics, which were experimentally discovered in the Si\u0026thinsp;\u0026lt;\u0026thinsp;P, Zn\u0026thinsp;\u0026gt;\u0026thinsp;samples with NC we studied [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIt should also be noted that with a decrease in the resistivity of the samples, the value of the vertical section of the CVC also decreases. Knowing the charge carrier concentrations at a given temperature, we calculated the positions of the Fermi level in these samples at T\u0026thinsp;=\u0026thinsp;300 K, which are F\u003csub\u003e1\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;0.35 eV, F\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;0.43 eV, and F\u003csub\u003e3\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;0.49 eV, respectively. Therefore, it can be assumed that in these samples the NCs act as traps with different concentrations and ionization energies, which are higher than the Fermi level. Let's consider that in the samples under study there are only NCs with different charge multiplicities. We can assume that the detected energy levels correspond to their different charge states.\u003c/p\u003e"},{"header":"4. Conclusions","content":"\u003cp\u003eBased on the studies of the electrical properties of silicon samples diffusion-doped with zinc, it was established that the CVC consists of several characteristic sections (the number of which can reach up to 6): linear, sublinear, superlinear, switching point, and section with NDC. Their number and voltage ranges depend on the temperature, degree of illumination, and resistivity of the sample.\u003c/p\u003e \u003cp\u003eThe sublinear sections of the CVC observed in p- and n-type Si\u0026thinsp;\u0026lt;\u0026thinsp;P, Zn\u0026thinsp;\u0026gt;\u0026thinsp;samples can be satisfactorily explained within the framework of the theory of the injection depletion effect. The observed quadratic dependences J \u0026sim; E\u003csup\u003e2\u003c/sup\u003e in the CVC can be associated with the influence of traps on conductivity. In the p- and n-type Si\u0026thinsp;\u0026lt;\u0026thinsp;P, Zn\u0026thinsp;\u0026gt;\u0026thinsp;samples we studied, the transfer of charge carriers in electric fields with a strength of less than 10\u003csup\u003e2\u003c/sup\u003e V/cm is mainly due to monopolar injection and is consistent with Lampert\u0026rsquo;s theory.\u003c/p\u003e \u003cp\u003eThe presence of a region of sharper current growth in the CVC, where \u003cem\u003eα\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;3, can be explained by the fact that in Si\u0026thinsp;\u0026lt;\u0026thinsp;P, Zn\u0026thinsp;\u0026gt;\u0026thinsp;p- and n-type samples at such electric field strengths, emptying (or ionization) of traps occurs, stimulated by the electric field.\u003c/p\u003e \u003cp\u003eThe observed features in the CVC are mainly associated with the formation of nano-sized multiply charged clusters, which significantly change the structure of the energy states of zinc atoms in silicon. As a result, instead of the well-known two acceptor energy levels corresponding to atomic zinc, a whole spectrum of deep donor energy levels of zinc nanoclusters appears lying in the range E\u0026thinsp;=\u0026thinsp;E\u003csub\u003eV\u003c/sub\u003e+(0.16\u0026thinsp;\u0026divide;\u0026thinsp;0.4) eV.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eDeclarations\u003c/h2\u003e \u003cp\u003e \u003cstrong\u003eEthical Approval\u003c/strong\u003e \u003cp\u003eNot applicable.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eCompeting Interests\u003c/strong\u003e \u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eE.A., S.S., and V.P. conceived and planned the experiments. M.R., N.M., and S.Q. carried out the experiments. S.S., and M.R. contributed to sample preparation. E.A., and B.Y. contributed to the interpretation of the results. E.A. took the lead in writing the manuscript. All authors provided critical feedback and helped shape the research, analysis, and manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThis study was supported by the Open Fund of Hubei Key Laboratory of Electronic Manufacturing and Packaging Integration (Wuhan University) (Grant No. EMPI2024017).\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e \u003cp\u003eNo datasets were generated or analyzed during the current study.\u003c/p\u003e\u003ch2\u003eCode Availability\u003c/h2\u003e \u003cp\u003eNot Applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eFuller CS, Morin FJ (1957) Phys Rev 105:379\u0026ndash;384\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMerk E, Hoyman J, Haller EE (1989) Solid State Commun 72:851\u0026ndash;854\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWeiss S, Beckman N, Kassing R (1990) Appl Phys A 50:151\u0026ndash;156\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eArzikulov EU, Radzhabova M, Quvondiqov SJ, Gulyamov G, East European (2023) J Phys 3:400\u0026ndash;405. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.26565/2312-4334-2023-3-43\u003c/span\u003e\u003cspan address=\"10.26565/2312-4334-2023-3-43\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBagrayev NT, Mirsaatov RM, Polovtsev IS, Yusupov A (1992) Semiconductors. 26: 481\u0026ndash;490\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBakhadirkhanov MK, Zikrillaev NF, Arzikulov EU (1991) Tech Phys Lett 17:1\u0026ndash;4\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNeul M, Sprave IV, Diebel LK, Zinkl LG, Fuchs F, Yamamoto Y, Vedder C, Bougeard D, Schreiber LR (2024) Phys Rev Mater 8:043801. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1103/PhysRevMaterials.8.043801\u003c/span\u003e\u003cspan address=\"10.1103/PhysRevMaterials.8.043801\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZikrillaev NF, Arzikulov EU (1991) Rep Uzbek Acad Sci 11:27\u0026ndash;30\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLampert MA, Mark P (1970) Current injection in solids. 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Technosphere, Moscow\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRafiq MA (2018) J Semicond. 39: 061002-1-061002-13. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1088/1674-4926/39/6/061002\u003c/span\u003e\u003cspan address=\"10.1088/1674-4926/39/6/061002\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"doped silicon, current-voltage characteristic, negative differential conductivity, low dimensional objects, zinc nanoclusters","lastPublishedDoi":"10.21203/rs.3.rs-4421869/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4421869/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis work is devoted to the study of current flow in diffusion-doped zinc silicon samples in the dark and when illuminated with integral light with an intensity in the range from 0.6 to 140 lx and at a temperature of 300 K. At T\u0026thinsp;=\u0026thinsp;300 K and in the dark, the view the current-voltage characteristic (CVC) contained all areas characteristic of semiconductors with deep energy levels. It was found that when illuminated with integral light, the type of CVCs of the studied Si samples depended on the value of the applied voltage, the electrical resistivity of the samples, the light intensity, and their number reached up to 6. In this case, linear, sublinear, and superlinear sections were observed, as well as the switching point (sharp current jump) and areas with negative differential conductivities (NDC). The existence of these characteristic areas of the applied voltage and their character depended on the intensity of the integral light. The experimental data obtained were interpreted in connection with the formation of low dimensional objects with the participation of multiply charged zinc nanoclusters in the bulk of silicon. They changed the energy band structure of single-crystal silicon, which affected generation-recombination processes in Si, leading to the types of CVCs observed in the experiment.\u003c/p\u003e","manuscriptTitle":"Current Mechanisms in Zinc Diffusion-doped Silicon Samples at T = 300 K","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-06-27 19:57:03","doi":"10.21203/rs.3.rs-4421869/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"54b7ebd6-b216-46ac-a683-3185b1a67958","owner":[],"postedDate":"June 27th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-07-11T05:36:08+00:00","versionOfRecord":[],"versionCreatedAt":"2024-06-27 19:57:03","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4421869","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4421869","identity":"rs-4421869","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}