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 bandgap 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.
@article{arxiv.2110.15500,
title = {Layer-dependent pressure effect on electronic structures of 2D black phosphorus},
author = {Shenyang Huang and Yang Lu and Fanjie Wang and Yuchen Lei and Chaoyu Song and Jiasheng Zhang and Qiaoxia Xing and Chong Wang and Yuangang Xie and Lei Mu and Guowei Zhang and Hao Yan and Bin Chen and Hugen Yan},
journal= {arXiv preprint arXiv:2110.15500},
year = {2021}
}