肖鹏同学的论文"Solution-processed three-dimensional RGO-MoS₂/pyramid Si heterojunction for ultrahigh-detectivity and ultra-broadband photodetection"发表在Adv. Mater.上

2018-06-21     来源:站内    关键词:揭建胜课题组     浏览量:119

Abstract
Molybdenum disulfide (MoS2), a typical two-dimensional metal dichalcogenides (2DMDs), has exhibited tremendous potential in optoelectronic device applications, especially in the photodetection. However, due to the weak light absorption of planar mono-/multilayers, limited cutoff wavelength edge, and lack of high-quality junction, most reported MoS2-based photodetectors show undesirable performance. Here, a structurized three-dimensional (3D) heterojunction of RGO-MoS2/pyramid Si was demonstrated, for the first time, via a simple solution-processed method. Owing to improved light absorption by pyramid structure, narrowed bandgap of MoS2 by imperfect crystallinity, and enhanced charge separation/transportation by inserted RGO, the assembled photodetector exhibited excellent performance in terms of large responsivity of 21.8 A W-1, extremely high detectivity up to 3.8 × 1015 Jones (Jones = cm Hz1/2 W-1) and ultra-broad spectrum response ranging from 350 nm (ultraviolet) to 4.3 μm (mid-wave infrared). These device parameters represent best results for MoS2-based self-driven photodetectors, and the detectivity value sets a new record for 2DMD-based photodetectors reported thus far. Prospectively, the design of novel 3D heterojunction could be extended to other 2DMDs, opening up the opportunities for a host of high-performance optoelectronic devices.