从理论上研究子电子-声子相互作用对Morse量子阱中光吸收系数的影响, 首先利用微扰论方法求出考虑极化子效应时的电子波函数和能级, 然后利用密度矩阵和迭代法得到光吸收系数的解析表达式, 最后以典型的GaAs/AlGaAs Morse 量子阱为例进行数值计算。结果表明, 极化子效应使光吸收系数比仅考虑电子的情况增大了, 并且在相同光强的情况下吸收饱和现象更明显; 极化子效应的影响随着阱的非对称性的增强而增大; 电声相互作用对电子能级的修正导致光吸收系数峰值向高能方向偏移。

The effect of the electron-phonon interaction on the optical absorptions is theoretically studied for electrons confined in Morse quantum wells. The wave functions and energy levels are described in Morse quantum well by perturbation theory when the electron-phonon interaction is considered, and analytic expression for the optical absorption is obtained by the compact density-matrix method and the iterative procedure. The numerical results for typical GaAs/AlGaAs material show that when considering the electron-phonon interaction the optical absorption coefficients are enhanced, and the total optical absorption is strongly bleached at the linear center. It is obtained that the larger the asymmetry of the quantum wells is, the sharper the peak will be when considering the electron-phonon interaction, and the greater influence of the polaron will be. Furthermore, the correction of electron-phonon interaction effect on the energies of the electron makes the peak shift to the aspect of the high energy.