Ab initio study of the linear and nonlinear optical properties of chalcopyrite CdGeAs2

作者：Yu You; Zhao Beijun^*; Zhu Shifu; Gao Tao; Hou Haijun; He Zhiyu

来源：Journal of Solid State Chemistry, 2012, 185: 264-270.

DOI：10.1016/j.jssc.2011.10.014

• CdGeAs2
• GW
• Linear optical
• Nonlinear optical

We present an ab initio theoretical study of the electronic, linear and nonlinear optical properties of CdGeAs2 using a pseudopotential plane-wave method. Specifically, we evaluate the band structure, density of states, charge density, the dielectric function epsilon(omega) and the second harmonic generation response susceptibility chi((2))(312)(-2 omega; omega,omega) over a large frequency range. As LDA underestimates the band gap, we have applied the GW approximation method to calculate the quasiparticle band structure and obtain an energy band gap in agreement with experiment. In this case the opening of the gap due to the GW correction can be used as scissor shift to calculate the linear and nonlinear optical properties. The intra- and inter-band contributions to the imaginary part of chi((2))(312)(-2 omega; omega,omega) are presented over a broad energy range. It is found that the small energy gap semiconductor CdGeAs2 has larger values of epsilon(1)(0) and chi((2))(312)(0) than other chalcopyrite structures.

• 出版日期2012-1
• 单位四川大学