Optical characterization of defects in narrow-gap HgCdTe for infrared detector applications

• 来源期刊: 中国物理B（英文版）
• 关键词: HgCdTe defects annealing procedures optical characterization
• 年，卷（期）: 2019,（1）
• 页码范围: 51-64
• 页数: 14页
• 语种: 英文
• DOI: 10.1088/1674-1056/28/1/017104

摘要

Narrow-gap Hg1?xCdxTe material with a composition x of about 0.3 plays an extremely important role in mid-infrared detection applications. In this work, the optical properties of doped HgCdTe with x ≈ 0.3 are reviewed, including the defects and defect levels of intrinsic VHg and the extrinsic amphoteric arsenic (As) dopants, which can act as shallow/deep donors and acceptors. The influence of the defects on the determination of band-edge electronic structure is discussed when absorption or photoluminescence spectra are considered. The inconsistency between these two optical techniques is demonstrated and analyzed by taking into account the Fermi level position as a function of composition, doping level, conductivity type, and temperature. The defect level and its evolution, especially in As-doped HgCdTe, are presented. Our results provide a systematic understanding of the mechanisms and help for optimizing annealing conditions towards p-type As-activation, and eventually for fabricating high performance mid-infrared detectors.