温度与拉伸应变调控体相黑磷的价带演化

Evolution of the 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17.8MeV/% 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。

关键词:ARPES; 温度; 拉伸应变; 体相黑磷; 价带顶偏移

Abstract:

Using angle-resolved photoemission spectroscopy (ARPES) combined with a thin-film stretching holder, the temperature-dependent band measurements of bulk black phosphorus were initially conducted, before performing band measurements under tensile strain at 200℃. The results show that as the heating temperature increases from 30℃ to 200℃, 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℃ 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 17.8MeV/% 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.

Key words:ARPES; temperature; tensile strain; bulk black phosphorus; VBM shift