Substrate/layer relationships in II–VIs

Abstract This review explores the scope of substrate/layer relationships in II–VI epitaxy. In addition to the lattice parameter mismatch, other important factors such as valence mismatch, polarity and thermal expansion match are considered. In some cases the lattice parameter mismatch is not the dominant factor in determining material quality such as ZnSe on GaAs. The ideal for high quality epilayers is to use lattice matched II–VI substrates but these have not always been available and alternative substrates have in some cases looked more attractive. Recent progress with CdTe and CdZnTe substrates is changing the prospect for II–VI substrates. However, issues such as surface preparation and cleaning are highlighted with newly available ZnSe substrates. Finally, the potential for II–VI growth onto microcrystalline and amorphous substrates is considered and possible approaches for promoting grain growth are discussed.