Layer-Dependent Pressure Effect on the Electronic Structure of 2D Black Phosphorus
Shenyang Huang, Yang Lu, Fanjie Wang, Yuchen Lei, Chaoyu Song, Jiasheng Zhang, Qiaoxia Xing, Chong Wang, Yuangang Xie, Lei Mu, Guowei Zhang, Hao Yan, Bin Chen, Hugen Yan
Abstract
Through infrared spectroscopy, we systematically study the pressure effect on electronic structures of few-layer black phosphorus (BP) with layer number ranging from 2 to 13. We reveal that the pressure-induced shift of optical transitions exhibits strong layer dependence. In sharp contrast to the bulk counterpart which undergoes a semiconductor to semimetal transition under ∼1.8 GPa, the band gap of 2 L increases with increasing pressure until beyond 2 GPa. Meanwhile, for a sample with a given layer number, the pressure-induced shift also differs for transitions with different indices. Through the tight-binding model in conjunction with a Morse potential for the interlayer coupling, this layer- and transition-index-dependent pressure effect can be fully accounted. Our study paves a way for versatile van der Waals engineering of two-dimensional BP.