Defects in ZnSe/ZnTe multiple quantum well-based pseudo-ohmic contacts to p-ZnSe

Abstract

The microstructure of ZnSe/ZnTe multiple quantum well-based pseudo-ohmic contacts to p-ZnSe was investigated using transmission electron microscopy and high-resolution transmission electron microscopy. In the case of samples consisting of five ZnSe/ZnTe multiple quantum wells, both pure edge Lomer dislocations and 60° dislocations were identified at the interface between the ZnSe/ZnTe multiple quantum wells and the ZnTe overlayer, along with partial dislocations bounding stacking faults. The dominant dislocations at the interface are Lomer dislocations. In the case of samples grown under group II-rich conditions, the interface exhibits corrugations. At the top and bottom of the corrugations, the Lomer dislocations are dominant and in the slope of the corrugations, 60° dislocations are dominant. In the case of samples grown using migration-enhanced epitaxy, V-shaped defects consisting of three dislocations associated with two stacking faults are formed. The total Burgers vector of the V-shaped defects is a〈100〉. The increasing total thickness and the number of ZnSe/ZnTe multiple quantum wells leads tend to make the dominant defects dissociated 60° dislocations.