Dai Mingjin, Chen Hongyu, Wang Fakun, Long Mingsheng, Shang Huiming, Hu Yunxia, Li Wen, Ge Chuanyang, Zhang Jia, Zhai Tianyou, Fu Yongqing, Hu PingAn
State Key Laboratory of Material Processing and Die and Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China.
Institutes of Physical Science and Information Technology, Anhui University, Anhui 230601, People's Republic of China.
ACS Nano. 2020 Jul 28;14(7):9098-9106. doi: 10.1021/acsnano.0c04329. Epub 2020 Jul 6.
Self-powered photodetectors with great potential for implanted medical diagnosis and smart communications have been severely hindered by the difficulty of simultaneously achieving high sensitivity and fast response speed. Here, we report an ultrafast and highly sensitive self-powered photodetector based on two-dimensional (2D) InSe, which is achieved by applying a device architecture design and generating ideal Schottky or ohmic contacts on 2D layered semiconductors, which are difficult to realize in the conventional semiconductors owing to their surface Fermi-level pinning. The as-fabricated InSe photodiode features a maximal lateral self-limited depletion region and a vertical fully depleted channel. It exhibits a high detectivity of 1.26 × 10 Jones and an ultrafast response speed of ∼200 ns, which breaks the response speed limit of reported self-powered photodetectors based on 2D semiconductors. The high sensitivity is achieved by an ultralow dark current noise generated from the robust van der Waals (vdW) Schottky junction and a high photoresponsivity due to the formation of a maximal lateral self-limited depletion region. The ultrafast response time is dominated by the fast carrier drift driven by a strong built-in electric field in the vertical fully depleted channel. This device architecture can help us to design high-performance photodetectors utilizing vdW layered semiconductors.
具有用于植入式医学诊断和智能通信巨大潜力的自供电光电探测器，因难以同时实现高灵敏度和快速响应速度而受到严重阻碍。在此，我们报道了一种基于二维（2D）InSe的超快且高灵敏度的自供电光电探测器，这是通过应用器件架构设计并在二维层状半导体上生成理想的肖特基或欧姆接触来实现的，由于传统半导体存在表面费米能级钉扎现象，在其上难以实现这种接触。所制备的InSe光电二极管具有最大横向自限制耗尽区和垂直完全耗尽沟道。它展现出1.26×10琼斯的高探测率和约200纳秒的超快响应速度，这打破了已报道的基于二维半导体的自供电光电探测器的响应速度限制。高灵敏度是由稳健的范德华（vdW）肖特基结产生的超低暗电流噪声以及因形成最大横向自限制耗尽区而具有的高光响应度实现的。超快响应时间由垂直完全耗尽沟道中强内建电场驱动的快速载流子漂移主导。这种器件架构有助于我们利用vdW层状半导体设计高性能光电探测器。
