Impurities And Defects

Investigating impurities and defects for any semiconductor material is an important topic. Much research has been devoted to impurity and defect states in wide-gap semiconductor materials. For the pseudobinary semiconductor alloy HgCdTe (mercury cadmium tellurium (MCT)), which is a good material for preparing infrared detectors, the investigation of its defects has a special significance. The behavior of impurities and defects in HgCdTe has been discussed in many papers in recent years. However, the research on impurities and defects of HgCdTe has encountered considerably more complexity and difficulty than that encountered in other semiconductors because of its narrow band gap, the low conduction band effective mass, the ease with which Hg vacancies are formed, and complex with other native point defects and impurities. Despite these difficulties, research in recent years have provided a basic description of impurities and defects, and their diffusion and photoelectric behavior in HgCdTe. For the narrow gap semiconductor material HgCdTe, we need to know which kind of impurities and defects exist in the material, their chemical composition and electrical activity, if they are p-type or n-type, the magnitude of the impurity concentration, the ionization energies of these defects, their impact on electrical and optical properties, how to experimentally observe their properties, and how to theoretically analyze their properties.