Molecular-beam epitaxy-grown HgCdTe infrared detector: Material physics, structure design, and device fabrication

Infrared (IR) detectors have important applications in numerous civil and military sectors. HgCdTe is one of the most important materials for IR detector manufacture. This review systematically discusses the progress of HgCdTe materials grown via molecular-beam epitaxy (MBE) for IR detection in terms of material physics, structure design, and fabrication. The material physics of HgCdTe includes crystal information, band structure, and electrical and optical properties. The characterization methods of the As-grown HgCdTe materials are also summarized. Then, four design structures of HgCdTe for IR detectors, with multilayer, superlattice, double-layer heterojunction, and barrier properties, which significantly improve the device performance, are discussed. The third section summarizes the studies on HgCdTe MBE-grown on different substrates, including CdZnTe, Si, and GaSb, in recent decades. This review discusses the factors influencing the growth of the HgCdTe film and their relationships and optimal conditions. Finally, we present the prospects and challenges associated with the fabrication and applications of HgCdTe materials for IR detectors.