Heterovalent semiconductor structures and devices grown by molecular beam epitaxy

Heterovalent structures consisting of group II-VI/group III-V compound semiconductors offer attractive properties, such as a very broad range of bandgaps, large conduction band offsets, high electron and hole mobilities, and quantum-material properties such as electric-field-induced topological insulator states. These properties and characteristics are highly desirable for many electronic and optoelectronic devices as well as potential condensed-matter quantum-physics applications. Here, we provide an overview of our recent studies of the MBE growth and characterization of zincblende II-VI/III-V heterostructures as well as several novel device applications based on different sets of these materials. By combining materials with small lattice mismatch, such as ZnTe/GaSb (Delta a/a similar to 0.13%), CdTe/InSb (Delta a/a similar to 0.05%), and ZnSe/GaAs (Delta a/a similar to 0.26%), epitaxial films of excellent crystallinity were grown once the growth conditions had been optimized. Cross-sectional observations using conventional and atomic-resolution electron microscopy revealed coherent interfaces and close to defect-free heterostructures. Measurements across CdTe/InSb interfaces indicated a limited amount (similar to 1.5 nm) of chemical intermixing. Results for ZnTe/GaSb distributed Bragg reflectors, CdTe/MgxCd1-xTe double heterostructures, and CdTe/InSb two-color photodetectors are briefly presented, and the growth of a rock salt/zincblende PbTe/CdTe/InSb heterostructure is also described.

Automated summary

This article provides an overview of research on zincblende II-VI/III-V heterostructures, focusing on several novel device applications based on these materials. The study found that by combining materials with small lattice mismatch, highly crystalline epitaxial films with almost defect-free heterostructures could be grown.