Effect of Conduction Band Non-Parabolicity on the Nonlinear Optical Properties in GaAs/Ga1-xAlxAs Double Semi-V-shaped Quantum Wells.

Zhi-Hai Zhang,Jian-Hui Yuan,Elmustapha Feddi,Kang-Xian Guo

doi:10.3390/ma12010078

Abstract

In this paper, we investigate the effect of conduction band non-parabolicity (NPBE) on the third harmonic generation(THG), the linear and nonlinear intersub-band optical absorption coefficients (OACs) related with electronic states of double semi-V-shaped GaAs/Ga1−xAlxAs quantum wells(QWs) by using the compact-density-matrix approach. Simultaneously, the work is performed in the position dependent effective mass in order to compute the electronic structure for the system by the finite difference and self-consistent techniques. We also compare the results with and without considering NPBE. It is found that: (1) the NPBE has a significant influence on the sub-band energy levels of double semi-V-shaped QWs, and (2) the amplitude and position of the resonant peaks of the THG and nonlinear OACs in the case of considering NPBE show complicated behavior due to the energy dependent effective mass m*(E) where the energy value was chosen self-consistently.

Highlights

Nowadays, the fundamental properties of low-dimensional semiconductor structures play an extremely important role in developing new technologies in various areas
The results show that the structure parameters of double quantum well (QW) and applied electric field have a significant effect on the nonlinear optical properties, and the magnitude of the second harmonic generation is 1–2 orders of magnitude higher than that in step single QW system [13,14]
It is observed that the energy levels are significantly reduced when considering the influence of the NPBE

Summary

Introduction

The fundamental properties of low-dimensional semiconductor structures play an extremely important role in developing new technologies in various areas. Chen et al studied the applied electric field on the nonlinear optical properties in symmetric and asymmetric double. Materials 2019, 12, 78 triangular QWs. The results show that the structure parameters of double QWs and applied electric field have a significant effect on the nonlinear optical properties, and the magnitude of the second harmonic generation is 1–2 orders of magnitude higher than that in step single QW system [13,14]. Yesilgul investigated the linear and nonlinear intersub-band OACs and refractive index changes in symmetric double semi-V-shaped QWs. The numerical results show that the geometrical parameters have a great effect on the optical characteristics [23]. Yesilgul et al calculated the effect of geometrical parameters on the linear, nonlinear OACs and refractive index changes of asymmetric double semi-V-shaped QWs [24].

Theory

Results and Discussions

Conclusions