Fabrication of Cost-Effective Nebulizer Sprayed In₂S₃ Thin Films for Photodetector Applications

The present study investigates the effect of precursor solution volume on the structural, morphological, compositional, optical, and electrical properties of In₂S₃ films. Thin films of In₂S₃ were deposited by a nebulizer spray pyrolysis technique on glass substrates with varying precursor solution volumes (4 mL, 8 mL, 12 mL, and 16 mL). X-ray diffraction studies confirmed the formation of the tetragonal phase and the compositional studies using energy-dispersive x-ray spectra showed the presence of only indium and sulfur. The energy bandgap of the films was found to be in the range of 2.51–2.4 eV. The I-V characteristics and photoresponses of the photodetectors including photosensitivity, responsivity, and detectivity were evaluated under visible light illumination. Enhanced photo-responsivity was observed with an increase in the precursor solution volume, with a maximum value of 0.213 AW⁻¹ observed for the thin film coated with 12 mL precursor solution volume. For the thin film coated with a volume of 12 mL precursor solution, external quantum efficiency of 69% and detectivity of 20 × 10⁹ Jones were observed. This In₂S₃ thin film may find application in the fabrication of efficient and cost-effective photodetector devices.