PDF(Pubmed)
Abstract：
Monolayer materials typically display intriguing temperature-dependent dielectric and optical properties, which are crucial for improving the structure and functionality of associated devices. Due to its unique photoelectric capabilities, monolayer WSe2 has recently received a lot of attention in the fields of atomically thin electronics and optoelectronics. In this work, we focus on the evolution of the temperature-dependent dielectric function (ε = ε1 + i ε2) of monolayer WSe2 over energies from 0.74 to 6.40 eV and temperatures from 40 to 350 K. We analyze the second derivatives of ε with respect to energy to accurately locate the critical points (CP). The dependence of the observed CP energies on temperature is consistent with the alternative domination of the declining exciton binding energy as the temperature increases.
摘要：
单层材料通常显示出有趣的温度依赖性介电和光学特性，这对于改善相关设备的结构和功能至关重要。由于其独特的光电能力，单层WSe2最近在原子级薄电子学和光电子学领域受到了很多关注。在这项工作中,我们专注于单层WSe2在0.74至6.40eV的能量和40至350K的温度下随温度变化的介电函数（ε=ε1iε2）的演变。我们分析了ε相对于能量的二阶导数，以精确定位临界点（CP）。观察到的CP能量对温度的依赖性与随着温度升高而下降的激子结合能的替代支配相一致。
