Open AccessFirst principles study on the electronic structures and optical properties of Na2Ge2Se5
Author(s) -
Xudong Cheng,
Haixin Wu,
Tang Xiao-Lu,
Zhenyou Wang,
Xiao Rui-Chun,
Huang Chang-Bao,
Youbao Ni
Publication year - 2014
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.63.184208
Subject(s) - materials science , refractive index , birefringence , density of states , absorption (acoustics) , absorption spectroscopy , electronic band structure , crystal (programming language) , dielectric , semiconductor , infrared , electronic structure , optoelectronics , optics , molecular physics , condensed matter physics , physics , computer science , composite material , programming language
The optimized crystal structure, electronic structure and optical properties of Na2Ge2Se5, an excellent nonlinear crystal, are investigated by using pseudo-potential plane-wave method based on the first principles. The band structure, density of states, bond population, dielectric function, reflection spectrum, absorption spectrum, and codex refractive index of optimized structure of Na2Ge2Se5 are calculated. The results indicate that Na2Ge2Se5 is indirect wide-band semiconductor. The electronic transitions are mainly composed of Ge-4s, Ge-4p, Se-4s and Se-4p. The optical properties are determined by the interaction between Ge and Se, while Na contributes little. The reflectance spectrum and absorption spectrum indicate that there is strong absorption to ultraviolet radiation and static refractive index is 2.133. Na2Ge2Se5 possesses moderate birefringence. The results indicate that Na2Ge2Se5 is a good candidate for the optical crystals in the infrared region.