<title>Coulomb effects in lattice-matched, strained, and strain-relieved low-dimensional semiconductors and their relevance for device simulation</title>

Abstract

ABSTRACTThe influence of Coulomb effects in the linear and nonlinear optical and electronic properties of semiconduc-tors with variable effective dimensionality is discussed in conjunction with bandstructure engineering tech-niques. The combined influence of valence bandcoupling, quantum confinement and many body effects areanalysed in lattice-matched, strained and strain-relived structures. Quasi-analytical results for linear! nonli-near absorption spectra are given for coherently coupled superlattices. Decoupled multiple quantum wells aretreated through rigorous numerical methods and the results are compared with analytical solutions in limiting cases. The theory is applied to the realistic simulation of lasers and optical computing devices. 1. INTRODUCTIONCoulomb effects play a major role in the near bandgap optical and electronic properties of semiconductorheterostructures. Those properties can be tailored through bandgap engineering techniques allowing the con- struction of custom-designed electronic, hybrid and all-optical devices.