【摘要】 在有效质量近似下,利用量子力学的密度矩阵理论,采用无限深势阱模型,从理论上计算了考虑极化子效应后在导带子带间跃迁时ZnS/CdSe柱型核壳结构量子点二次电光效应(QEOE)和电吸收过程(EA)的三阶极化率。通过数值计算,分析了电子-LO声子和电子-IO声子相互作用对ZnS/CdSe柱型核壳结构量子点二次电光效应和电吸收过程的三阶极化率的影响。结果表明,极化子效应对二次电光效应的三阶极化率χQEDE(3)和电吸收过程的三阶极化率χE(3A)都有很大影响,并且影响的大小与量子点的尺寸大小有关。更多还原

【Abstract】 The effect of the electron-phonon interaction on the quadratic electro-optic effect(QEOE) and electro-absorption process (EA) was investigated theoretically for electrons confined in a core-shell quantum dot. The interactions of electrons with different phonon modes in the core-shell system,including the confined longitudinal optical (LO) and the interface optical (IO) phonon modes,were investigated. We carried out a detailed calculation of quadratic electro-optic effects(QEOE)and electro-absorption process(EA) on a ZnS/CdSe core-shell quantum dot as a function of pump photon energy with different incident photon energy and under different quantum dot size. The results revealed that the polaron effects are quite important especially around the peak value of the third-order susceptibility.更多还原