TY - JOUR
T1 - Defect levels characterized by photoconductivity and thermally stimulated current in CdZnTe crystals
AU - Xu, Lingyan
AU - Feng, Tao
AU - Jie, Wanqi
N1 - Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/4/15
Y1 - 2021/4/15
N2 - Deep-level defects in CdZnTe (CZT) crystals were studied by combining photoconductivity (PC) and thermally stimulated current (TSC) measurements. The stretched-exponential function could well describe the time-dependent photocurrent decay kinetics, and the decay time constant was fitted to be ~54 s for CZT1 and ~98 s for CZT2, respectively. TSC spectra were analyzed through SIMPA fitting, and the total defect density was calculated to be about 1.14 × 1016 cm−3 in CZT1 and 1.80 × 1016 cm−3 in CZT2, respectively. Deep donor (Te antisites) could be considered as dominating the photoconductivity decay process. The electron mobility was fitted in Time-of-Flight (TOF) spectra to be about 783 cm2/Vs in CZT1 and 717 cm2/Vs in CZT2, respectively. Approximately the same electron mobility of the two CZT crystals corresponds to similar concentration of all the defect traps. The mobility-lifetime (μτ) product for electrons could be fitted by Hecht equation to be about 1.61 × 10−3 cm2/V in CZT1 and 3.01 × 10−4 cm2/V in CZT2, respectively. Higher concentration of deep donor (Te antisites) in CZT2 compared to that in CZT1 will lead to lifetime reduction and the resultant lower (μτ)e product.
AB - Deep-level defects in CdZnTe (CZT) crystals were studied by combining photoconductivity (PC) and thermally stimulated current (TSC) measurements. The stretched-exponential function could well describe the time-dependent photocurrent decay kinetics, and the decay time constant was fitted to be ~54 s for CZT1 and ~98 s for CZT2, respectively. TSC spectra were analyzed through SIMPA fitting, and the total defect density was calculated to be about 1.14 × 1016 cm−3 in CZT1 and 1.80 × 1016 cm−3 in CZT2, respectively. Deep donor (Te antisites) could be considered as dominating the photoconductivity decay process. The electron mobility was fitted in Time-of-Flight (TOF) spectra to be about 783 cm2/Vs in CZT1 and 717 cm2/Vs in CZT2, respectively. Approximately the same electron mobility of the two CZT crystals corresponds to similar concentration of all the defect traps. The mobility-lifetime (μτ) product for electrons could be fitted by Hecht equation to be about 1.61 × 10−3 cm2/V in CZT1 and 3.01 × 10−4 cm2/V in CZT2, respectively. Higher concentration of deep donor (Te antisites) in CZT2 compared to that in CZT1 will lead to lifetime reduction and the resultant lower (μτ)e product.
KW - A1. Defects
KW - A1. Impurities
KW - A2. Bridgman technique
KW - B2. Semiconducting II-VI materials
UR - http://www.scopus.com/inward/record.url?scp=85101041846&partnerID=8YFLogxK
U2 - 10.1016/j.jcrysgro.2021.126050
DO - 10.1016/j.jcrysgro.2021.126050
M3 - 文章
AN - SCOPUS:85101041846
SN - 0022-0248
VL - 560-561
JO - Journal of Crystal Growth
JF - Journal of Crystal Growth
M1 - 126050
ER -