Optical properties of monolayer, multilayer, and bulk BiI3 studied using time-dependent density functional theory
Optical properties of monolayer, multilayer, and bulk BiI3 studied using time-dependent density functional theory
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使用瞬态密度泛函理论研究单层、多层和块状 BiI3 的光学性质
DOI：
10.1103/physrevb.103.115409
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发表时间：
2021
影响因子：
3.7
通讯作者：
Nakamura Koichi
中科院分区：
文献类型：
--
作者：
Habe Tetsuro;Nakamura Koichi
我们研究了单层和分层的光学性质，发现激子仅存在于单层晶体中。我们利用含时密度泛函理论计算了介电函数的能谱。块状晶体是一种原子层状半导体，其带隙对应于可见光的频率。对块体晶体的数值计算结果证实与以前的实验结果是一致的，并不依赖于除单层的层数。我们揭示了激子出现在与单层晶体中的带间激发相关的共振峰下方。这种独特的光学性质可以在光吸收或差反射光谱中直接观察到，并将单层晶体与叠层晶体区分开来。
We investigate the optical property of monolayer and layeredand reveal the presence of excitons only in the monolayer crystal. We evaluate the energy spectrum of a dielectric function by using time-dependent density functional theory. Bulk crystal ofis an atomic layered semiconductor with the band gap corresponding to the frequency of visible light. The numerical result for the bulk crystal is confirmed to be consistent with the previous experimental results and does not depend on the number of layers except the monolayer. We reveal the excitons appearing below the resonant peak associated with the interband excitation in the monolayer crystal. The unique optical property can be directly observed in the optical absorption or differential reflectance spectrum and distinguish the monolayer crystal from the stacked.