Heterointerface control of ZnSe based II–VI laser diodes

Abstract

The density of pre-existing crystal defects such as stacking faults is reduced less than 3 × 10 3 cm −2 when there is a GaAs buffer layer and when a GaAs layer is irradiated with Zn flux prior to ZnSe growth. This progress in controlling a GaAs/ZnSe heterointerface has made possible a ZnCdSe/ZnSSe/ZnMgSSe separate-confinement heterostructure laser diode with a lifetime of over 100 h at room temperature under CW conditions. We believe that we have entered into a stage where the operation of II–VI laser diodes is limited by recombination-enhanced defect reactions. We have observed surface roughening in ZnSe layers, as well as in ZnSSe and ZnMgSSe layers, all grown under II-rich conditions. The compositional modulation in ZnMgSSe is indicated to be caused by corrugations on the surface, but not by the instability of the material.