Zinc indium sulfide (ZnIn₂S₄): a promising candidate material towards next-gen photodetection

As fundamental components of optoelectronic systems, photodetectors have found extensive applications in various domains. However, traditional light-sensing materials have encountered substantial obstacles in further achieving device miniaturization, flexibility, multi-functionalization, etc. Among numerous photosensitive materials, two-dimensional layered materials (2DLMs) manifest distinctive benefits including a dangling-bond-free surface, outstanding bendability and thickness-customized band structure. Zinc indium sulfide (ZnIn₂S₄), a novel ternary 2DLM, stands out on account of direct bandgap, excellent stability, wide range property tunability and favorable bandgap size, which enables well-balanced suppression of thermal excitation and an effective spectral range. In reality, the past decade has witnessed the dramatic advancement of ZnIn₂S₄-based photodetectors. However, the research findings are scattered and there is still a lack of systematic summarization of relevant progress. To address this issue, this review presents, for the first time, a comprehensive overview of ZnIn₂S₄-based photodetectors. It starts by presenting the fundamental properties of ZnIn₂S₄. Next, ZnIn₂S₄-based photodetectors are systematically introduced by classifying them into photoconductive-type detectors and photodiodes. The primary emphasis is placed on elucidating the fundamental mechanisms responsible for the competitive light-sensing properties. Finally, suggestions for future directions of this rapidly advancing field have been proposed, aiming to navigate upcoming research endeavors in the future.