Yoon Hoon Hahn, Ahmed Faisal, Dai Yunyun, Fernandez Henry A, Cui Xiaoqi, Bai Xueyin, Li Diao, Du Mingde, Lipsanen Harri, Sun Zhipei
Department of Electronics and Nanoengineering, Aalto University, FI-00076 Aalto, Finland.
QTF Centre of Excellence, Department of Applied Physics, Aalto University, FI-00076 Aalto, Finland.
ACS Appl Mater Interfaces. 2021 Dec 15;13(49):58927-58935. doi: 10.1021/acsami.1c18606. Epub 2021 Dec 2.
Graphene-based van der Waals heterostructures are promising building blocks for broadband photodetection because of the gapless nature of graphene. However, their performance is mostly limited by the inevitable trade-off between low dark current and photocurrent generation. Here, we demonstrate a hybrid photodetection mode based on the photogating effect coupled with the photovoltaic effect via tunable quantum tunneling through the unique graphene/BiSe heterointerface. The tunneling junction formed between the semimetallic graphene and the topologically insulating BiSe exhibits asymmetric rectifying and hysteretic current-voltage characteristics, which significantly suppresses the dark current and enhances the photocurrent. The photocurrent-to-dark current ratio increases by about a factor of 10 with the electrical tuning of tunneling resistance for efficient light detection covering the major photonic spectral band from the visible to the mid-infrared ranges. Our findings provide a novel concept of using tunable quantum tunneling for highly sensitive broadband photodetection in mixed-dimensional van der Waals heterostructures.
基于石墨烯的范德华异质结构因其石墨烯的无隙特性而有望成为宽带光电探测的构建模块。然而，它们的性能大多受到低暗电流与光电流产生之间不可避免的权衡限制。在此，我们展示了一种基于光门控效应并通过独特的石墨烯/铋硒异质界面的可调谐量子隧穿与光伏效应相结合的混合光电探测模式。半金属石墨烯与拓扑绝缘体铋硒之间形成的隧道结呈现出不对称整流和滞后电流 - 电压特性，这显著抑制了暗电流并增强了光电流。随着隧穿电阻的电调谐，光电流与暗电流之比提高了约10倍，实现了从可见光到中红外范围的主要光子光谱带的高效光探测。我们的研究结果提供了一种在混合维度范德华异质结构中利用可调谐量子隧穿实现高灵敏度宽带光电探测的新概念。
