摘要
All-inorganic lead-free halide perovskites have attracted interest owing to their high ambient and thermal stabilities,excellent optoelectronic properties,and environmental friendliness.Herein,the bismuth-based halide perovskite Cs_(3)Bi_(2)Br_(9)single crystals were successfully grown to a diameter of 12 mm and length of 40 mm using a modified Bridgman method for the first time.The resistivity and transmittance of transparent and crack-free Cs_(3)Bi_(2)Br_(9)single crystal are~6.8×10^(11)Ωcm and~80%,respectively.The carrier mobility of the(−120)plane is 0.17 cm^(2)V^(−1)s^(−1)along the[010]orientation(b axis),and the trap density is 9.7×10^(10)cm^(−3).Moreover,Cs_(3)Bi_(2)Br_(9)single crystals exhibit excellent potential for X-ray detection,including a high absorption coefficient,a superior X-ray sensitivity of~230.4μC Gyair^(−1)cm^(−2),and an ultra-low and no-drift dark current density of~17.8 pA mm−2,which enables lower noise and is also beneficial to the ultralow detection limit for X-ray detectors.Our study shows that Cs_(3)Bi_(2)Br_(9)is a promising candidate for X-ray detection applications.
近年来,全无机无铅卤化物钙钛矿以其良好的环境稳定性和热稳定性、优异的光电性能以及环境友好性而受到广泛关注.本文采用改进的垂直布里奇曼法首次生长出直径12 mm、长度约40 mm、透明性良好的Cs_(3)Bi_(2)Br_(9)单晶.生长的Cs_(3)Bi_(2)Br_(9)单晶的电阻率约为6.8×10^(11)Ωcm,透过率约为80%.在(−120)晶面内,载流子迁移率为0.17 cm^(2)V^(−1)s^(−1),缺陷态密度为9.7×10^(10)cm^(−3).在X射线探测方面,Cs_(3)Bi_(2)Br_(9)单晶最大灵敏度约为230.4μC Gyair−1 cm^(−2);暗电流密度约为17.8 pA mm^(−2),且没有漂移现象,这表明Cs_(3)Bi_(2)Br_(9)单晶具有更小的暗电流噪声,有利于获得更低的检测限.
基金
supported by the National Natural Science Foundation of China (51972194, 51602178, 51932004 and 61975098)
the 111 Project 2.0 (BP2018013)
the National Key Research and Development Program of China (2016YFB1102201 and 2018YFB0406502)
the Fundamental Research Funds of Shandong University
the State Key Laboratory of Solidification Processing in Northwestern Polytechnical University (NWPU) (SKLSP202019)
Shandong Provincial Key Research and Development Program (2018GGX102003)
