Study on Creation and Annihilation of electrons and holes in Compound Alloy semiconductors

我们用推广的CPA理论研究了对角无序的Al-xA*xB型化合物混晶的电子态。我们发现：1)当势能εB大于或小于εA和εA*时，混晶的电子能谱随组成的变化呈现单调变化。另一方面，如果εB位于εA和εA*之间，电子能谱表现出大的带隙弯曲，有时带隙变为零。我们还利用多个载流子的适当组态坐标图研究了深能级缺陷引起的载流子俘获和瞬时诱导晶格振动之间反馈和膨胀机制的可能性。对晶格运动的经典处理，我们自洽地模拟了相互作用模的时间演化以及电子(S)和空穴(S)的一系列非热俘获。当激活能E_(Ate)和E_(ACTH)都较小时，一系列连续的非热俘获增强，并且可能在较高的载流子密度下发生。然而，我们发现晶格振动幅度膨胀的可能性主要取决于少数俘获率和声子频率分布的相对宽度。

We have theoretically studied the electronic states in A1-xA* xB type compound mix crystal with diagonal disorder using an extension of CPA. We found that 1) if the potential energyεB is larger or less than bothεA andεA*, the electronic energy spectrum of the mix crystal shows monotonous change in the composition dependence. On the other hand, 2) ifεB is located betweenεA andεA*, the electronic energy spectrum shows a large band gap bowing and the band gap sometimes becomes zero. We also studied possibility of feedback and inflation mechanism among carrier captures by a deep-level defect and transient induced lattice vibrations using proper configuration coordinate diagrams for many carriers. Treating the lattice motion classically we selfconsistently simulated the time evolution of the interaction mode and a series of athermal captures of electron(s) and hole(s). When both the activation energies E acte and E acth are small, a series of successive athermal captures is enhanced and probable for high carrier densities, however, we found that thepossibility of inflation in the amplitude of the lattice vibration critically depends on the minority capture rate and the relative width of the phonon frequency distribution.