Li Genglin, Fu Jintao, Sun Feiying, Nie Changbin, Wu Jun
School of Optoelectronic Engineering, Chongqing University of Posts and Telecommunications, Chongqing 400065, China.
Chongqing School, University of Chinese Academy of Sciences, Chongqing 400714, China.
Nanomaterials (Basel). 2023 Jan 12;13(2):322. doi: 10.3390/nano13020322.
Position-sensitive detectors (PSDs) are of great significance to optical communication, automatic alignment, and dislocation detection domains, by precisely obtaining the position information of infrared light spots which are invisible to human eyes. Herein, a kind of PSD based on graphene/germanium (Ge) heterojunction architecture is proposed and demonstrated, which exhibits amplified signals by unitizing the charge injection effect. Driven by the graphene/Ge heterojunction, a large number of photogenerated carriers diffuse from the incident position of the light spot and subsequently inject into graphene, which ultimately generates a photoresponse with high efficiency. The experimental results show that the device can exhibit a fast response speed of 3 μs, a high responsivity of ~40 A/W, and a detection distance of 3000 μm at the 1550 nm band, which hints that the graphene/Ge heterojunction can be used as an efficient platform for near-infrared light spot position sensing.
位置敏感探测器（PSD）对于光通信、自动对准和位错检测领域具有重要意义，它能够精确获取人眼不可见的红外光斑的位置信息。在此，我们提出并展示了一种基于石墨烯/锗（Ge）异质结结构的PSD，该PSD通过利用电荷注入效应实现信号放大。在石墨烯/Ge异质结的驱动下，大量光生载流子从光斑的入射位置扩散，随后注入到石墨烯中，最终高效地产生光响应。实验结果表明，该器件在1550 nm波段可呈现3 μs的快速响应速度、约40 A/W的高响应度以及3000 μm的检测距离，这表明石墨烯/Ge异质结可作为近红外光斑位置传感的有效平台。
