Photodetector performance under blue–green–red light in ZnTe thin films grown by the quasi-closed volume method

This study delves into the performance of zinc telluride (ZnTe) thin films as photodetectors under blue, green, and red light. The research focuses on ZnTe films grown using the quasi-closed volume (QCV) method, a cost-effective and scalable technique. Key topics include the structural and morphological characterization of the films, their optical properties, and their photoelectrical performance. The study reveals that ZnTe thin films exhibit p-type conductivity and a direct bandgap of approximately 2.2 eV. Under visible illumination, the ZnTe photodetector shows a wavelength-dependent photoresponse, with the highest sensitivity and fastest response under blue light. The study also explores the sublinear photocurrent–power relationship, indicating trap-assisted conduction dominated by intrinsic defects. Despite moderate responsivity and external quantum efficiency, the device demonstrates stable, reproducible, and fast photoresponse behavior. The findings validate the reliability of the QCV method for optoelectronic applications and highlight ZnTe's potential for future visible-light photodetector devices.