Enhancing The Optoelectronic Properties of Nebulizer Sprayed In2S3 Thin Films For Photodetector Applications

Abstract In the present work, the versatile Indium sulfide thin films (In2S3) are deposited on glass substrates using nebulizer assisted spray pyrolysis technique at 350 °C for visible light detection application. The effect of the molar concentration of indium and sulfur on the structure, morphology, optical characteristics, and photo-sensing capability of the prepared In2S3 films were systematically studied in the range of 0.01 M to 0.03 M. The structural analysis showed a maximum crystallite size of 36 nm for 0.03 M sample. The morphological image from the scanning electron microscope showed a homogeneous large size grained surface of In2S3 film completely covering the substrate. The indium to the sulfur ratio in the prepared films ranged from 1.02 to 1.16 as the molar concentration was raised from 0.01 to 0.03 M. All the prepared films showed a good absorption in the ultraviolet and visible region of the electromagnetic spectra. The sample prepared at 0.03 M was found to have a minimum band gap of 2.38 eV and a maximum PL intensity at 480 nm. The I-V characteristics show a photocurrent of 1.4 × 10-5 A under visible light for an external bias voltage of ± 5 V. A maximum responsivity of 2.74 A/W, detectivity of 2.65 × 1010 Jones was exhibited by 0.03 M sample with a high EQE of 63.9 %. The prepared In2S3 thin film may find application as a photodetector.