Au掺杂HgCdTe材料的光电特性

Au掺杂是改善光伏型HgCdTe红外探测器性能的一种技术途径，通过Au掺杂来取代HgCdTe材料中的本征的Hg空位，可以提高材料的少子寿命和少子扩散长度。采用液相外延技术生长了Au掺杂的HgCdTe外延材料，Au的掺杂浓度为~8×1015/cm3，通过富Hg退火技术来抑制材料中的Hg空位，Hg空位的浓度控制在1~2×1015/cm3。变温霍尔测试表明，退火材料中的受主杂质能级为8~12 meV，并且与退火条件相关。采用Au掺杂材料和离子注入成结工艺制备了截止波长为14 μm的甚长波红外焦平面器件，测试结果显示，用Au掺杂取代Hg空位掺杂，可以显著提高红外探测器的光响应率，探测器的内量子效率可以达到95%以上。

Photoelectric characteristics of HgCdTe with Au-doping

Au-doping is one of the approaches to improve the performance of HgCdTe photovoltaic infrared detectors. The minority-carrier lifetime and diffusion length in HgCdTe could be improved by replacing the intrinsic Hg-vacancy with the doped Au. The Au-doping HgCdTe films were grown by liquid phase epitaxy method. The concentration of the doped Au was about 8×1015/cm3. A Hg-rich annealing technique was applied to suppress the Hg vacancies in the film and the Hg-vacancy concentration of 1-2×1015/cm3 could be achieved. The acceptor energy level in the annealed material was 8-12 meV measured by the temperature dependent Hall method, which was related to the annealing condition. The IR Focal Plane Array(IRFPA) of 14 μm cut-off wavelength was fabricated using the combination of Au-doping material and Ion-implanting technique. The results show that the replacement of Hg-vacancy with Au will greatly increase the responsivity of the detector and the inner quantum efficiency of the detector could exceed 95%.