PROCEEDINGS OF SPIE, THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING
Abstract
In the present paper we discuss the electronic properties of semiconductor heterojunctions, focusing on the band offset problem. We address interface-specific phenomena, where the conditions of growth -- including controlled contamination and strain effects -- may significantly alter the properties of the junction. We study the effects of ultrathin intralayers (i.e., heterovalent implantation) both at homojunctions (such as GaAs/Ge/GaAs) and heterojunctions (such as GaAs/Si/AlAs). In both cases, our theory demonstrates how the intralayers control the band offset: this result is confirmed by recent experimental observation in several systems. We then consider the band-offset engineering at lattice-mismatched heterojunctions, studying the paradigmatic case GaAs/Si. We evaluate the band-offset for several fully relaxed inequivalent interfaces. Both macroscopic strain and microscopic morphology effects are considered.
