Photodetectors based on sensitized two-dimensional transition metal dichalcogenidesA review

Atomically thin transition metal dichalcogenides (TMDCs), such as WS2 and MoS2, have opened up new opportunities for the next generation of optoelectronics owing to their unique properties such as optical transparency, high carrier mobility, widely tunable band gap, and strong light-matter interaction. The photodetection performance relies primarily on the light absorption efficiency and separation efficiency of photoexcited electron-holes. The photodetectors with all broadband response, high photoconductive gain, high response speed, and high detectivity is arduous challenge to realize using one photo-active material. Building of photodetectors composed of two or more light absorber materials of different band gaps was an efficient route to realize high performance light detection. The application of a thin sensitizing layer atop the TMDCs has proven to be a viable route to improve the photodetection performance due to the efficient charge separation at the interface, and fast charge transfer process due to the high carrier mobility. In this article, we review the progress made toward hybrid photodetector based on TMDCs with various sensitizers from metal to large band-gap semiconductor in architectures from zero-dimensional quantum dot to two-dimensional crystal.