论文标题
黑色磷的非平衡带拓宽，差距重新归一化和带反向
Non-equilibrium Band Broadening, Gap Renormalization and Band Inversion in Black Phosphorus
论文作者
论文摘要
黑色磷（BP）是一个分层的半导体，具有高载体迁移率，各向异性光学响应和宽带隙可调性。鉴于其在光电设备中的应用，了解瞬态光诱导的效果至关重要。在这里，我们通过时间和角度分辨的光发射光谱BP在其原始状态下进行研究，并且在存在鲜明的情况下，通过CS吸附化学诱导了鲜明的分裂。我们表明，照相载体触发带隙重新归一化和由Pauli Blocking引起的并发价带。在有偏见的样品中，光激发导致数百mV的长寿命（NS）表面光电压抵消了CS诱导的表面带弯曲的平衡。这使我们能够从表面电子状态中解散散装，并阐明在散装样品中观察到的带反转的机制。
Black phosphorous (BP) is a layered semiconductor with high carrier mobility, anisotropic optical response and wide bandgap tunability. In view of its application in optoelectronic devices, understanding transient photo-induced effects is crucial. Here, we investigate by time- and angle-resolved photoemission spectroscopy BP in its pristine state and in the presence of Stark splitting, chemically induced by Cs ad-sorption. We show that photo-injected carriers trigger bandgap renormalization and a concurrent valence band attening caused by Pauli blocking. In the biased sample, photoexcitation leads to a long-lived (ns) surface photovoltage of few hundreds mV that counterbalances the Cs-induced surface band bending. This allows us to disentangle bulk from surface electronic states and to clarify the mechanism underlying the band inversion observed in bulk samples.
