Two‐Dimensional Indium Chalcogenides: From Fundamental Properties to Next‐Generation Optoelectronic Devices

Abstract 2D indium chalcogenides, such as InSe and In ₂ Se ₃ , represent a significant class of functional materials characterized by tunable band gaps, exceptional carrier mobility, and robust light–matter interactions. This review thoroughly examines synthesis techniques, including chemical vapor deposition, molecular beam epitaxy, mechanical, and liquid exfoliation methods. It further highlights cutting‐edge characterization methodologies such as atomic force microscopy, scanning electron microscopy, and Raman spectroscopy, providing essential insights into the optoelectronic properties of these materials. The remarkable features of 2D indium chalcogenides facilitate their implementation in diverse optoelectronic applications, notably high‐performance photodetectors, polarization‐sensitive devices, and imaging systems. These materials also offer broadband spectral responsiveness and compatibility with van der Waals heterostructures, enhancing device performance. However, critical challenges such as scalability, environmental stability, and interface quality still hinder their widespread technological adoption. The review addresses these issues by recommending refined fabrication approaches, sophisticated interface engineering, and innovative encapsulation techniques. Finally, it outlines promising future directions, emphasizing scalable synthesis, hybrid device engineering, and the integration of machine learning, thereby paving the way for next‐generation photodetection technologies. This comprehensive review underscores the transformative potential of 2D indium chalcogenides and establishes a clear roadmap for overcoming existing challenges to realize their capabilities thoroughly.