Research progress on improving the performance of MoS2 photodetector

Abstract

Abstract Two-dimensional layered materials have attracted increasing attention due to their unique structures and outstanding mechanical and physical properties. Transition metal dichalcogenides (TMDs) possess unique physical properties and optical properties that meet the basic requirements of photodetectors. As representative TMDs, MoS2 has excellent mechanical properties due to its strong covalent bonds and great elasticity. The monolayer MoS2 has a direct bandgap of around 1.8 eV. In addition, MoS2-based optoelectronic devices have high switching ratio and carrier mobility. However, due to the characteristic of atomic-scale thickness, the light-harvesting ability of layered TMDs is very weak, which largely limits the responsivity and detection rate of photodetectors, thus inhibiting the practical application of such devices. The slow photo response rate is also a problem that often occurs in TMDs devices. Researchers have reported several strategies to improve the performance of TMDs-based photodetectors. At present, there are two main optimization schemes, namely surface modification, and heterostructure construction. The utilization of metal plasmon effect and the construction of heterojunctions are both effective means to improve the performance of MoS2 photodetectors. These schemes can improve the light absorption capability of MoS2 and broaden the range of light detection. However, there are also disadvantages of the complex processes and limited enhancement effects in large-area fabrication. Therefore, it is of vital significance to further explore the response range and performance of MoS2 photodetectors.