Investigation of the growth of high quality CdZnTe(211) films with ZnTe buffer layer: experiment and first-principles calculations

HgCdTe-based infrared detectors dominate high-performance infrared detection due to their tunable bandgap, quantum efficiency, extended carrier lifetime, and high-temperature performance. However, conventional CdZnTe substrates for epitaxial growth of HgCdTe materials are expensive and limited in size, hindering the fabrication of a large-size focal plane array. Hence, the exploration of new alternative substrate is conducive to the development of high-performance nano-optoelectronics. This study explores CdZnTe films with a ZnTe buffer layer as an alternative substrate material, which achieves low-cost, high-rate as well as high quality. Using close-spaced sublimation, we achieved 15 µm/h growth rates with decent crystalline quality. The ZnTe buffer layer reduces lattice mismatch between GaAs and CdZnTe, filters threading dislocations, and enhances growth island morphology, thereby decreasing the possibility of twinning. First-principles calculations revealed the buffer layer lowers system energy, improving crystallization. This work provides insights into optimizing compound semiconductor films, enhancing HgCdTe material performance, and offering a promising approach to address substrate limitations in HgCdTe infrared technology.