Threshold behavior of the Einstein oscillator, electron-phonon interaction, band-edge absorption, and small hole polarons in LiNbO${}_{3}$:Mg crystals

Threshold behavior of the Einstein oscillator, electron-phonon interaction, band-edge absorption, and small hole polarons in LiNbO $_{3}$ :Mg crystals

Feifei Xin, Zhaohui Zhai, Xiaojie Wang, Yongfa Kong, Jingjun Xu, and Guoquan Zhang

Phys. Rev. B 86, 165132 – Published 24 October 2012

Abstract

Based on the Einstein oscillator model and the Urbach rule, we study the electron-phonon interaction and the band-edge structure of LiNbO $_{3}$ :Mg. We report on the concentration threshold behavior of the Einstein oscillator, the electron-phonon interaction, the band-edge absorption, and the light-induced small hole polarons O $^{-}$ in LiNbO $_{3}$ :Mg crystals with increasing Mg-doping concentration. The result gives a fundamental microscopic mechanism of the concentration threshold behavior related to the band-edge optical properties and the light-induced charge transport of LiNbO $_{3}$ :Mg crystals, and is helpful to optimize LiNbO $_{3}$ for applications such as nonlinear optics.