期刊
ACS APPLIED MATERIALS & INTERFACES
卷 12, 期 9, 页码 10772-10780出版社
AMER CHEMICAL SOC
DOI: 10.1021/acsami.9b19904
关键词
graphene; h-BN; 2D material; photodetector; hot carrier; tunneling
资金
- National Research Foundation of Korea (NRF) - Korean government (MSIT) [NRF-2018R1A2B2008069]
- R&D program of MOTIE/KEIT [10064078]
- Multi-Ministry Collaborative R&D Program through the National Research Foundation of Korea - KNPA
- MSIT
- MOTIE
- ME
- NFA [2017M3D9A1073539]
- National Research Foundation of Korea [2018K2A9A2A06017491]
- Institute for Basic Science [IBS-R011-D1]
- Korea Evaluation Institute of Industrial Technology (KEIT) [10064078] Funding Source: Korea Institute of Science & Technology Information (KISTI), National Science & Technology Information Service (NTIS)
- National Research Foundation of Korea [IBS-R011-D1-2020-A00] Funding Source: Korea Institute of Science & Technology Information (KISTI), National Science & Technology Information Service (NTIS)
Graphene is one of the most promising materials for photodetectors due to its ability to convert photons into hot carriers within approximately 50 fs and generate long-lived thermalized states with lifetimes longer than 1 ps. In this study, we demonstrate a wide range of vertical photodetectors having a graphene/h-BN/Au heterostructure in which an hexagonal boron nitride (h-BN) insulating layer is inserted between an Au electrode and graphene photoabsorber. The photocarriers effectively tunnel through the small hole barrier (1.93 eV) at the Au/h-BN junction while the dark carriers are highly suppressed by a large electron barrier (2.27 eV) at the graphene/h-BN junction. Thus, an extremely low dark current of similar to 10(-13) A is achieved, which is 8 orders of magnitude lower than that of graphene lateral photodetector devices (similar to 10(-5) A). Also, our device displays an asymmetric photoresponse behavior due to photothermionic emission at the graphene/h-BN and Au/h-BN junctions. The asymmetric behavior generates additional thermal carriers (hot carriers) to enable our device to generate photocurrents that can overcome the Schottky barrier. Furthermore, our device shows the highest value of the I-ph/I-dark ratio of similar to 225 at 7 nm thick h-BN insulating layer, which is 3 orders of magnitude larger than that of the previously reported graphene lateral photodetectors without any active materials. In addition, we achieve a fast response speed of 12 mu s of rise time and 5 mu s of fall time, which are about 100 times faster than those of other graphene integrated photodetectors.
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