First-principles study of the bandgap renormalization and optical property ofβ-LiGaO_(2)  

作　　者：方党旗 Dangqi Fang(MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter,School of Physics,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter,School of Physics,Xi’an Jiaotong University,Xi’an 710049,China

出　　处：《Chinese Physics B》2023年第4期87-92,共6页中国物理B（英文版）

基　　金：Project support from the National Natural Science Foundation of China(Grant No.11604254);the Natural Science Foundation of Shaanxi Province;China(Grant No.2019JQ-240)。

摘　　要：Theβ-LiGaO_(2)with an orthorhombic wurtzite-derived structure is a candidate ultrawide direct-bandgap semiconductor.In this work,using the non-adiabatic Allen-Heine-Cardona approach,we investigate the bandgap renormalization arising from electron-phonon coupling.We find a sizable zero-point motion correction of-0.362 eV to the gap atΓ,which is dominated by the contributions of long-wavelength longitudinal optical phonons.The bandgap ofβ-LiGaO_(2)decreases monotonically with increasing temperature.We investigate the optical spectra by comparing the model Bethe-Salpether equation method with the independent-particle approximation.The calculated optical spectra including electron-hole interactions exhibit strong excitonic effects,in qualitative agreement with the experiment.The contributing interband transitions and the binding energy for the excitonic states are analyzed.

关 键 词：wide-bandgap semiconductor electron-phonon coupling bandgap renormalization optical spectrum first-principles calculation 

分 类 号：O471[理学—半导体物理]