期刊
ACS NANO
卷 13, 期 3, 页码 3269-3279出版社
AMER CHEMICAL SOC
DOI: 10.1021/acsnano.8b09032
关键词
transition-metal dichalcogenide; graphene; photodetectors; indium adatoms; ultrafast response
类别
资金
- Ministry of Science and Technology of Taiwan [MOST 107-2119-M-007-011-MY2, MOST 106-2119-M-007-008-MY3, MOST 106-2628-M-007-003-MY3]
- Academia Sinica [AS-TP-106-A07]
- JSPS-KAKENHI [JP16H06333, 18K14119]
One of the primary limitations of previously reported two-dimensional (2D) photodetectors is a low frequency response (<< 1 Hz) for sensitive devices with gain. Yet, little efforts have been devoted to improve the temporal response of photodetectors while maintaining high gain and responsivity. Here, we demonstrate a gain of 6.3 x 10(3) electrons per photon and a responsivity of 2.6 x 10(3) A/W while simultaneously exhibiting an ultrafast response time of 40-65 mu s in a hybrid photodetector that consists of graphene-WS2-graphene junctions covered with indium (In) adatoms atop. The resultant responsivity is 6 orders of magnitude higher than that of conventional photodetectors comprising solely of a Au-WS2-Au junction. The photogain is provided mainly by the adsorbed In adatoms, from which photogenerated electrons can be transferred to the WS2 channel, while holes remain trapped in In adatoms, leading to a photogating effect as electrons are recirculating during the residence of holes in In adatoms. At a gate voltage near the Dirac point of graphene, a detectivity of D* = 2.2 x 10(12) Jones and an ON/OFF ratio of 10(4) are achieved. The enhanced performance of the device can be attributed partly to the transparent graphene/WS2 contact and partly to the strong capacitive coupling of the In adatoms with the WS2 channel, which enables ultrafast carrier dynamics.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据