High Detectivity and Transparent Few‐Layer MoS2/Glassy‐Graphene Heterostructure Photodetectors

• DOI: 10.1002/adma.201706561
• Publication Date: 2018-01-30T07:46:26Z
• Authors: Hao Xu; Xiaoyu Han; Xiao Dai; Wei Liu; Jiang Wu; Juntong Zhu; Dongyoung Kim; Guifu Zou; Kimberley A. Sablon; Andrei Sergeev; Zhengxiao Guo; Huiyun Liu
• Keywords: glassy-graphene; heterostructures; photodetectors; 02 engineering and technology; MoS2; 0210 nano-technology; 7. Clean energy; 01 natural sciences; density functional theory; 0104 chemical sciences

AbstractLayered van der Waals heterostructures have attracted considerable attention recently, due to their unique properties both inherited from individual two‐dimensional (2D) components and imparted from their interactions. Here, a novel few‐layer MoS2/glassy‐graphene heterostructure, synthesized by a layer‐by‐layer transfer technique, and its application as transparent photodetectors are reported for the first time. Instead of a traditional Schottky junction, coherent ohmic contact is formed at the interface between the MoS2 and the glassy‐graphene nanosheets. The device exhibits pronounced wavelength selectivity as illuminated by monochromatic lights. A responsivity of 12.3 mA W−1 and detectivity of 1.8 × 1010 Jones are obtained from the photodetector under 532 nm light illumination. Density functional theory calculations reveal the impact of specific carbon atomic arrangement in the glassy‐graphene on the electronic band structure. It is demonstrated that the band alignment of the layered heterostructures can be manipulated by lattice engineering of 2D nanosheets to enhance optoelectronic performance.