From Anomalous to Normal: Temperature Dependence of the Band Gap in Two-Dimensional Black Phosphorus

Shenyang Huang, Fanjie Wang, Guowei Zhang, Chaoyu Song, Yuchen Lei, Qiaoxia Xing, Chong Wang, Yujun Zhang, Jiasheng Zhang, Yuangang Xie, Lei Mu, Chunxiao Cong (+2 others)
2020 Physical Review Letters  
The temperature dependence of the band gap is crucial to a semiconductor. Bulk black phosphorus is known to exhibit an anomalous behavior. Through optical spectroscopy, here we show that the temperature effect on black phosphorus band gap gradually evolves with decreasing layer number, eventually turns into a normal one in the monolayer limit, rendering a crossover from the anomalous to the normal. Meanwhile, the temperature-induced shift in optical resonance also differs with different
more » ... on indices for the same thickness sample. A comprehensive analysis reveals that the temperature-tunable interlayer coupling is responsible for the observed diverse scenario. Our study provides a key to the apprehension of the anomalous temperature behavior in certain layered semiconductors.
doi:10.1103/physrevlett.125.156802 pmid:33095618 fatcat:eoochd3mmva4xbfkrm7u4yano4