Properties, Synthesis, and Device Applications of 2D Layered InSe

Van der Waals layered indium selenide (InSe) is an emerging star of the 2D semiconducting materials because of its excellent fundamental properties, such as ultrahigh carrier mobility, layer-tunable bandgap, large elastic deformability, and rich polytypes. In addition, 2D layered indium selenide has demonstrated outstanding device performance including photodetector, field-effect transistor, memory and synapse, mechanical and gas sensor, which has offered a new chance to next-generation electrical and optoelectronic devices. This review presents a comprehensive summary of recent progress in 2D layered indium selenide. The novel fundamental properties and synthetic methods are summarized. Also, the indium selenide-based state-of-the-art electronic/optoelectronic devices, such as a functional field-effect transistor, photodetector, and mechanical and gas sensors are systematically summarized. The techniques to enhance the performances of devices are also discussed. Finally, a brief discussion on the challenges and future opportunities as a guideline for this field is provided.