A versatile photodetector assisted by photovoltaic and bolometric effects
Wei Jiang, Tan Zheng, Binmin Wu, Hanxue Jiao, Xudong Wang, Yan Chen, Xiaoyu Zhang, Meng Peng, Hailu Wang, Tie Lin, Hong Shen, Jun Ge, Weida Hu, Xiaofeng Xu, Xiangjian Meng, Junhao Chu, Jianlu Wang
Abstract
The advent of low-dimensional materials with peculiar structure and superb band properties provides a new canonical form for the development of photodetectors. However, the limited exploitation of basic properties makes it difficult for devices to stand out. Here, we demonstrate a hybrid heterostructure with ultrathin vanadium dioxide film and molybdenum ditelluride nanoflake. Vanadium dioxide is a classical semiconductor with a narrow bandgap, a high temperature coefficient of resistance, and phase transformation. Molybdenum ditelluride, a typical two-dimensional material, is often used to construct optoelectronic devices. The heterostructure can realize three different functional modes: (i) the p-n junction exhibits ultrasensitive detection (450 nm-2 μm) with a dark current down to 0.2 pA and a response time of 17 μs, (ii) the Schottky junction works stably under extreme conditions such as a high temperature of 400 K, and (iii) the bolometer shows ultrabroad spectrum detection exceeding 10 μm. The flexible switching between the three modes makes the heterostructure a potential candidate for next-generation photodetectors from visible to longwave infrared radiation (LWIR). This type of photodetector combines versatile detection modes, shedding light on the hybrid application of novel and traditional materials, and is a prototype of advanced optoelectronic devices.