毛杰同学的论文"Ultrafast, Broadband Photodetector Based on MoSe₂/Silicon Heterojunction with Vertically Standing Layered Structure Using Graphene as Transparent Electrode"发表在Adv. Sci.上。

2016-03-21     来源:站内    关键词:揭建胜课题组     浏览量:55
Abstract

Advances in the photocurrent conversion of layered molybdenum diselenide (MoSe2) have enabled the realization of a variety of important optoelectronic devices such as photovoltaics and photodetectors owing to its extraordinary properties. However,photodetectors based on MoSe2 mono-/multilayer sheets still suffer from low response speed and relatively weak light response arising from low light absorption. Herein, it is demonstrated that high-quality MoSe2/Si heterojunctions could be constructed by depositing n-type MoSe2 film on p-type Si substrate. The relatively thick MoSe2 film could offer strong light absorption from ultraviolet (UV) to visible and to near-infrared (NIR) light. Significantly, the MoSe2 film fabricated by sputtering possessed a vertically standing layered structure, greatly facilitating the separation and transport of photogenerated carriers. Collection of the carriers was further enhanced by the use of graphene (Gr) transparent electrode on the top. Owing to the unique device structure, the Gr/MoSe2/Si photodetectors exhibited outstanding device characteristics in terms of broadband response ranging from 365 to 1310 nm, high detectivity of 7.13 × 10^10 Jones, and ultrafast response speed of 270 ns. These parameters are significantly better than mono-/multilayer MoSe2-based photodetectors. Our work paves the way for development of high-performance optoelectronic devices based on MoSe2/Si heterojunctions.