A noticeable improvement in opto-electronic properties of nebulizer sprayed In2S3 thin films for stable-photodetector applications

Abstract

In the present work, the versatile Indium sulfide thin film (In2S3) are deposited on glass substrates by using nebulizer assisted spray pyrolysis technique at 350 °C for ultra violet (UV) light detection application. The effect of the of indium and sulfur molar concentrations on the structure, morphology, optical characteristics, and photo-sensing capability of the prepared In2S3 films were systematically examined in the range of 0.01 M–0.03 M. The structural analysis of the 0.03 M sample showed a maximum crystallite size of 36 nm. The morphological image from the scanning electron microscope showed a homogeneous, large size grained surface of In2S3 completely covering the substrate. As the molar concentration was raised from 0.01 to 0.03 M, the indium to the sulfur ratio in the prepared films ranged from 1.02 to 1.16. All the prepared films showed good absorption in the ultraviolet region of the electromagnetic spectrum. 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 680 nm. The I–V characteristics show a photocurrent of 1.4 × 10−5 A under UV light of wavelength 365 nm 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 can be used as active material in photodetectors.