Electric field control of opical transitions in semiconductor superlattice spaces

为了追求半导体量子结构中光跃迁的电场可控性，研究了三种不同类型的GaAs/AIAs超晶格，得到了以下结果：电场对非对称双阱超晶格中光学跃迁的影响对于单位周期内由非对称双阱对组成的新型双周期超晶格，已经观察到并阐明了由宽阱和窄阱的Stark-ladder态之间的共振耦合引起的光学跃迁的反交叉和激子效应。对于一种具有阱和势垒双周期性的新型完全不对称超晶格，根据基于传递矩阵法的约束本征能和振子强度的理论计算，阐明了观察到的跃迁能扇形图和通过更薄的势垒的更强耦合而增强的抗交叉。在含有孤立单量子阱的单周期超晶格的光吸收光谱中，观察到外加电场控制下的电子和空穴共振，并利用有效质量近似内的传递矩阵计算进行了分析。

In order to pursue the electric-field controlability of optical transitions in semiconductor quantum structures, three different-types of GaAs/AIAs superlattices have been investigated and the following results are obtained.1. Electric field effects on optical transitions in an asymmetric double-well superlatticeFor a new-type biperiodic superlattice consisting of asymmetric double-well pairs in a unit period, anticrossings as well as excitonic effects of the optical transitions have been observed and clarified, originating from the resonant coupling between the Stark-ladder states belonging to the wider and narrower wells.2. Electric field effects on optical transitions in a perfectly asymmetric double period superlatticeFor a new-type of perfectly asymmetric superlattice having the well and barrier biperiodicity, the observed transition energy fan diagram and enhanced anticrossings due to stronger couplings through the thinner barriers have been elucidated in the light of theoretical calculations of the confined eigenenergies and the oscillator strengths based on the transfer matrix method.3. Electric field control of optical transitions due to interactions between superlattice ladder and single quantum well statesElectron as well as hole resonances controlled by the applied electric field have been observed in the optical absorption spectra of a monoperiodic superlattice which contains an isolated single quantum well in the middle, and analyzed with the help of transfer matrix calculations within the effective mass approximation.