温度与拉伸应变调控体相黑磷的价带演化

The evolutions of valence band in bulk black phosphorus regulated by temperature and tensile strain

摘要:

利用角分辨光电子能谱仪（ARPES）结合薄膜拉伸样品托，对体相黑磷分别进行了变温度和200℃下拉伸应变调控的能带测试。结果显示，随着加热温度从30℃增加到200℃，价带顶（valence band maximum, VBM）逐渐向深能级偏移。造成这种变化的原因是晶格的受热膨胀弱化了层间相互作用。随后，200℃下的应变ARPES测试表明，随着沿zigzag方向的拉伸应变的增加，VBM呈现出线性的浅能级偏移趋势，高温下的VBM偏移率达到了17.8 meV/% strain。这是由于在高温下，拉伸应变引起的面外方向的晶格收缩量更大，相应的层间相互作用增强更多，从而导致VBM发生更显著的偏移。

Abstract:

Using Angle-Resolved Photoemission Spectroscopy (ARPES) combined with a thin-film stretching holder, the temperature-dependent band measurements of bulk black phosphorus were conducted firstly, and then the band measurements under tensile strain at 200°C were performed. The results show that as the heating temperature increases from 30°C to 200°C, the valence band maximum (VBM) gradually shifts towards deeper levels. This change is attributed to the weakening of interlayer interactions due to thermal expansion of the lattice. The strain-ARPES measurements at 200°C indicate that as the tensile strain along the zigzag direction increases, the VBM exhibits a linear shift towards shallower levels, with a shift rate of 17.8 meV/% strain. This is because at high temperatures, the tensile strain induces a greater lattice contraction in the out-of-plane direction, resulting in a more significant enhancement of interlayer interactions, which subsequently leads to a more pronounced VBM shift.