N,Sb和单分子层数对GaAs/GaInNAsSb超晶格性能的影响

Effects of Sb, N, and period on the electronic properties of GaAs/GaInNAsSb superlattices

用Keating的价力场 (valenceforcefield)模型和蒙特卡罗方法计算了GaAs GaInNAsSb超晶格中键的分布、原子的精确位置以及应变 .用折叠谱法 (foldedspectrummethod)结合Williamson经验赝势法计算了GaAs GaInNAsSb超晶格应变条件下的电子结构 .讨论了N和Sb原子以及超晶格单分子层数对电子结构的影响 .发现导带底电子态在N原子周围的局域化减小了光跃迁矩阵元 ,从而影响了该超晶格的发光性能 .计算并讨论了超晶格的电子和空穴的有效质量 .

We have calculated the bond distributions and atom positions of GaAs/GaInNAsSb superlattices using Keating's semi-empirical valence force field (VFF) model and Monte Carlo simulation. The electronic structures of the superlattices are calculated using folded spectrum method (FSM) combined with an empirical pseudopotential (EP) proposed by Williamson et al.. The effects of N and Sb on superlattice energy levels are discussed. We find that the deterioration of the optical properties induced by N can be explained by the localization of the conduction-band states around the N atom. The electron and hole effective masses of the superlattices are calculated and compared with the effective masses of the bulk GaAs and GaInAs.