In the present work, ZnS thin films were deposited onto Si substrate using the chemical bath deposition technique [1], with a deposition time of 75min and 100min, and subsequently the deposited thin films were used to fabricate Ag/ZnS/p-Si/Ag heterojunction devices to study their visible light photodetection properties under illumination intensity of 30mW/cm² and 56mW/cm² under applied forward bias voltage of 0V and 5V [2, 3]. Glancing incidence X-ray diffraction analysis confirmed the cubic zinc blende phase of the deposited thin films, and Scherrer analysis revealed a crystallite size of 2.2nm. Surface morphology was studied using scanning electron microscopy and scanning transmission electron microscopy. X-ray photoelectron spectroscopy confirmed the presence of desired Zn²⁺ and S^2- chemical species in the deposited thin films. Optical transmittance spectra revealed the higher transmittance of the ZnS thin film deposited for 75min, while Tauc analysis of the optical absorbance spectra revealed that the deposited thin films had an energy band gap of 3.9eV. Photoluminescence emission spectra revealed the emission due to recombination transitions via defect related energy sites. Analysis of the visible light photodetection parameters revealed that the fabricated devices exhibited high-performance, especially in terms of response and recovery times, with stable, reproducible and rapid-switching on-off cycles, indicating the potential for application in optical sensing, detection or communication [4-5].

• Gupta, S., Kumar, A., Mukherjee, S., Kushwah, K.K., Mahobia, S.K., Patharia, P., Kushwaha, A., Yadav, D., Dwivedi, U.K., Kumar, S. and Choubey, R.K. (2023). “Temperature-dependent study of the fabricated ZnS/p-Si heterojunction.” Physica B: Condensed Matter, 657, 414831.
• Dong, T., Simões, J. & Yang, Z., (2020). “Flexible photodetector based on 2D materials: processing, architectures, and applications.” Advanced Materials Interfaces, 7(4), 1901657.
• Ezhilmaran, B., Patra, A., Benny, S., Sreelakshmi, M.R., Akshay, V.V., Bhat, S.V. & Rout, C.S. (2021). “Recent developments in the photodetector applications of Schottky diodes based on 2D materials.” Journal of Materials Chemistry C, 9(19), 6122-6150.
• Zhou, Y.H., Zhang, Z.B., Xu, P., Zhang, H. & Wang, B., (2019). “UV-visible photodetector based on I-type heterostructure of ZnO-QDs/monolayer MoS 2.” Nanoscale research letters, 14, 1-10.
• Kim, D., Park, K., Lee, J.H., Kwon, I.S., Kwak, I.H. & Park, J., (2021). “Anisotropic 2D SiAs for High‐Performance UV–Visible Photodetectors.” Small, 17(10), 2006310.