人工晶体学报2025，Vol.54Issue(6)：960-969,10.DOI:10.16553/j.cnki.issn1000-985x.2024.0321
移动加热器法生长的CZT晶体内部点缺陷精细调控研究
Fine Modulation of Internal Point Defects in CZT Crystals Grown by the Traveling Heater Method
摘要
Abstract
There are a large number of intrinsic point defects and related composite defects in the growing CdZnTe(CZT)crystal.It is crucial to obtain information on these point defects and their effects.This article designs high-temperature Cd atmosphere annealing of CZT crystals,and controls the degree of atomic diffusion through annealing time to regulate the distribution of sample point defects.For Te-rich CZT crystals grown by the traveling heater method(THM),multiple advanced techniques,including photo-induced current transient spectroscopy(PICTS),low-temperature photoluminescence(PL),I-V tests and alpha-induced transient charge analysis,were utilized to investigate the relationship between the point defect distribution and various optoelectronic properties such as resistivity,carrier mobility and charge collection efficiency.The point defect measurement results indicate that TeCd defects dominate in the as-grown sample,with a concentration of 4.47×1013 cm-3 and a capture cross-section of 9.34×10-16 cm2.After 24 h of Cd annealing,the defect distribution changes,and Cdi defects gradually become dominant,reaching a concentration of 4.49×1013 cm-3 with a reduced capture cross-section of 5.82×10-19 cm2.The electrical performance test results indicate that the carrier mobility and charge collection efficiency are related to the total concentration of CZT point defects,the internal electric field is determined by the TeCd with the largest capture cross-section.Samples that were annealed under Cd vapor for 6 h are characterized by high charge collection efficiency,high mobility(697 cm2·V-1·s-1)and uniform internal electric field distribution,though the resistivity is relatively low.During the diffusion process,the positions of VCd and TeCd are preferentially occupied by Cd atoms,leading to an exponential decrease in the concentration of A-centers and TeCd,which is regarded as the main cause for the reduction in resistivity.关键词
碲锌镉/点缺陷/环境退火/移动加热器法/光电特性/电阻率Key words
CdZnTe/point defect/ambient annealing/THM/photoelectric characteristic/resistivity分类
数理科学引用本文复制引用
喻超,张博,王琦琦,王希,胡于南,梁小燕,张继军,闵嘉华,王林军..移动加热器法生长的CZT晶体内部点缺陷精细调控研究[J].人工晶体学报,2025,54(6):960-969,10.基金项目
国家自然科学基金(11675099) （11675099）
