TY - JOUR
T1 - Optical and electronic anisotropies in perovskitoid crystals of Cs3Bi2I9 studies of nuclear radiation detection
AU - Sun, Qihao
AU - Xu, Yadong
AU - Zhang, Hongjian
AU - Xiao, Bao
AU - Liu, Xin
AU - Dong, Jiangpeng
AU - Cheng, Yuanbo
AU - Zhang, Binbin
AU - Jie, Wanqi
AU - Kanatzidis, Mercouri G.
N1 - Funding Information:
This work has been nancially supported by National Natural Science Foundations of China (No. 51872228 and U1631116), National Key Research and Development Program of China (2016YFE0115200 and 2016YFF0101301), and the Fundamental Research Funds for the Central Universities (3102017zy057 and 3102018jcc036). At Northwestern University this work was supported by the Department of Homeland Security ARI program with grant 2014-DN-077-ARI086-01.
PY - 2018
Y1 - 2018
N2 - The halide perovskitoid compound Cs3Bi2I9 (CBI) has attracted considerable interest as a semiconductor because of its outstanding stability and reduced toxicity compared with lead-based halide perovskites. Here, we report the growth of nuclear radiation detection grade CBI bulk crystals (Φ 15 × 60 mm3) with a high resistivity of over 1010 Ω cm using a modified vertical Bridgman method. Because of their layered crystal structures we investigated the anisotropy in the optical and electrical properties using different crystal orientations. The CBI(001) sample exhibits a resistivity of ∼1012 Ω cm compared to ∼1010 Ω cm for the CBI(100) sample. This is due to the anisotropic mobility in the two crystallographic directions. Using 425 nm LED (∼200 mW cm−2) illumination CBI(001) possesses a superior optical response with a switching ratio of over 40, which is critically higher than that of CBI(100) (<2). Detectors of 2 mm thickness show a capability of detecting 241Am@5.49 MeV α particles, with good peak discrimination. A full width at half maximum (FWHM) of 32% was obtained under a bias of 560 V. Simultaneously, the electron mobility and mobility lifetime (μτ) were calculated to be 6.10 cm2 V−1 s−1 and 2.03 × 10−5 cm V−1, respectively. First-principles density functional theory calculations confirm the crystallographic anisotropy of the carrier effective masses. In addition, a significant X-ray sensitivity of 111.9 μC Gy−1 cm−2 for a CBI detector was observed, under 80 kVp X-rays at an electrical field of 450 V cm−1.
AB - The halide perovskitoid compound Cs3Bi2I9 (CBI) has attracted considerable interest as a semiconductor because of its outstanding stability and reduced toxicity compared with lead-based halide perovskites. Here, we report the growth of nuclear radiation detection grade CBI bulk crystals (Φ 15 × 60 mm3) with a high resistivity of over 1010 Ω cm using a modified vertical Bridgman method. Because of their layered crystal structures we investigated the anisotropy in the optical and electrical properties using different crystal orientations. The CBI(001) sample exhibits a resistivity of ∼1012 Ω cm compared to ∼1010 Ω cm for the CBI(100) sample. This is due to the anisotropic mobility in the two crystallographic directions. Using 425 nm LED (∼200 mW cm−2) illumination CBI(001) possesses a superior optical response with a switching ratio of over 40, which is critically higher than that of CBI(100) (<2). Detectors of 2 mm thickness show a capability of detecting 241Am@5.49 MeV α particles, with good peak discrimination. A full width at half maximum (FWHM) of 32% was obtained under a bias of 560 V. Simultaneously, the electron mobility and mobility lifetime (μτ) were calculated to be 6.10 cm2 V−1 s−1 and 2.03 × 10−5 cm V−1, respectively. First-principles density functional theory calculations confirm the crystallographic anisotropy of the carrier effective masses. In addition, a significant X-ray sensitivity of 111.9 μC Gy−1 cm−2 for a CBI detector was observed, under 80 kVp X-rays at an electrical field of 450 V cm−1.
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U2 - 10.1039/c8ta09525f
DO - 10.1039/c8ta09525f
M3 - Article
AN - SCOPUS:85057527958
VL - 6
SP - 23388
EP - 23395
JO - Journal of Materials Chemistry A
JF - Journal of Materials Chemistry A
SN - 2050-7488
IS - 46
ER -