UV-Vis-NIR Broadband Dual-Mode Photodetector Based on Graphene/InP Van Der Waals Heterostructure

作者：Mingyang Shen, Hao Liu, Qi Wang, Han Ye, Xueguang Yuan, Yangan Zhang, Bo Wei, Xue He, Kai Liu, Shiwei Cai, Yongqing Huang, Xiaomin Ren · 发表于：Sensors · 年份：2025 · DOI：10.3390/s25072115 · 被引用次数：5 · 研究领域：2D Materials and Applications、Graphene research and applications、Nanowire Synthesis and Applications

Dual-mode photodetectors (DmPDs) have attracted considerable interest due to their ability to integrate multiple functionalities into a single device. However, 2D material/InP heterostructures, which exhibit built-in electric fields and rapid response characteristics, have not yet been utilized in DmPDs. In this work, we fabricate a high-performance DmPD based on a graphene/InP Van der Waals heterostructure in a facile way, achieving a broadband response from ultraviolet-visible to near-infrared wavelengths. The device incorporates two top electrodes contacting monolayer chemical vapor deposition (CVD) graphene and a bottom electrode on the backside of an InP substrate. By flexibly switching among these three electrodes, the as-fabricated DmPD can operate in a self-powered photovoltaic mode for energy-efficient high-speed imaging or in a biased photoconductive mode for detecting weak light signals, fully demonstrating its multifunctional detection capabilities. Specifically, in the self-powered photovoltaic mode, the DmPD leverages the vertically configured Schottky junction to achieve an on/off ratio of 8 × 103, a responsivity of 49.2 mA/W, a detectivity of 4.09 × 1011 Jones, and an ultrafast response, with a rising time (τr) and falling time (τf) of 2.8/6.2 μs. In the photoconductive mode at a 1 V bias, the photogating effect enhances the responsivity to 162.5 A/W. This work advances the development of InP-based multifunctional optoelectronic devices.