Momentum-matching and band-alignment van der Waals heterostructures for high-efficiency infrared photodetection
Yunfeng Chen, Congwei Tan, Zhen Wang, Jinshui Miao, Xun Ge, Tiange Zhao, Kecai Liao, Haonan Ge, Yang Wang, Fang Wang, Yi Zhou, Peng Wang, Xiaohao Zhou, Chongxin Shan, Hailin Peng, Weida Hu
Abstract
Two-dimensional (2D) infrared photodetectors always suffer from low quantum efficiency (QE) because of the limited atomically thin absorption. Here, we reported 2D black phosphorus (BP)/Bi 2 O 2 Se van der Waals (vdW) photodetectors with momentum-matching and band-alignment heterostructures to achieve high QE. The QE was largely improved by optimizing the generation, suppressing the recombination, and improving the collection of photocarriers. Note that momentum-matching BP/Bi 2 O 2 Se heterostructures in k -space lead to the highly efficient generation and transition of photocarriers. The recombination process can be largely suppressed by lattice mismatching–immune vdW interfaces. Furthermore, type II BP/Bi 2 O 2 Se vdW heterostructures could also assist fast transport and collection of photocarriers. By constructing momentum-matching and band-alignment heterostructures, a record-high QE of 84% at 1.3 micrometers and 76.5% at 2 micrometers have been achieved in BP/Bi 2 O 2 Se vdW photodetectors.