All-inorganic Cs_(3)Bi_(2)I_(9)(CBI)halide perovskites are sought to be candidate for photoelectrical materials because of their low toxicity and satisfactory stability.Unfortunately,the discrete molecular[Bi2I9]3−clu...All-inorganic Cs_(3)Bi_(2)I_(9)(CBI)halide perovskites are sought to be candidate for photoelectrical materials because of their low toxicity and satisfactory stability.Unfortunately,the discrete molecular[Bi2I9]3−clusters limit the charge-transport behaviors.Herein,the defect halide perovskite based on trivalent Bi^(3+)is expanded to Cs_(3)Bi_(2)I_(6)Br_(3)(CBIB).Centimeter-size CBIB single crystal(Φ15×70 mm^(3))was grown by the vertical Bridgeman method.The powder X-ray diffraction analysis shows that CBIB has structure with lattice parameters of a=b=8.223Å,c=10.024Å,α=β=90°andγ=120°.The density functional theory(DFT)calculations demonstrate that the charge density distribution was enhanced after the dimensional expansion.The enhancement of carrier transport ability of(00l)in-plane is characterized before and after dimensional improvement.The obtained CBIB(001)exhibited an electron mobility up to 40.03 cm^(2)V^(−1)s^(−1)by time-of-flight(TOF)technique,higher than 26.46 cm^(2)V^(−1)s^(−1)of CBI(001).Furthermore,the X-ray sensitivity increases from 707.81μC Gy^(−1)cm^(−2)for CBI(001)to 3194.59μC Gy−1 cm^(−2)for CBIB(001).This research will deepen our understanding of Bi-based perovskite materials and afford more promising strategies for lead-free perovskite optoelectronic devices modification.展开更多
Bi_4 Si_3 O_(12):RE(BSO:RE, RE = Eu^(3+), Sm^(3+), Ho^(3+), Tb^(3+)) crystals were grown by the modified vertical Bridgeman method, and doping effects on scintillation properties were investigated. Under γ-ray irradi...Bi_4 Si_3 O_(12):RE(BSO:RE, RE = Eu^(3+), Sm^(3+), Ho^(3+), Tb^(3+)) crystals were grown by the modified vertical Bridgeman method, and doping effects on scintillation properties were investigated. Under γ-ray irradiation, the light yield of BSO doped with small doses of Eu^(3+) increases slightly, and the energy resolution improves significantly compared to pure BSO, therefore the ability of distinguishing between particles will be improved for BSO crystals with a small amount of Eu^(3+) dopant. The results show that a small amount of Eu^(3+) doping can sensitize the Bi^(3+) ions. The sensitization effect enables the reduction of intrinsic defects, and thus improves the scintillation properties. However, the relative light yield of BSO:Tb(1.0 mol%) crystal is 4.3%, which is smaller than 5.0% of pure BSO. The improved light yield and energy resolution in the BSO:Eu and BSO:Sm crystals are considered an impressive achievement in the optimization of this scintillator which is already suitable for applications such as dual-readout calorimeters and homogeneous hadron calorimeters.展开更多
基金supported by the National Natural Science Foundations of China(Nos.51872228,U2032170 and 51802262)the National Key Research and Development Program of China(2016YFE0115200 and 2016YFF0101301)+2 种基金the Natural Science Foundations of Shaanxi Province(2019JQ-459 and 2020JC-12)the Natural Science Basic Research Plan in Shaanxi Province of China(2019ZDLGY04-07)the Fundamental Research Funds for the Central Universities(D5000210906 and 3102020QD0408)。
文摘All-inorganic Cs_(3)Bi_(2)I_(9)(CBI)halide perovskites are sought to be candidate for photoelectrical materials because of their low toxicity and satisfactory stability.Unfortunately,the discrete molecular[Bi2I9]3−clusters limit the charge-transport behaviors.Herein,the defect halide perovskite based on trivalent Bi^(3+)is expanded to Cs_(3)Bi_(2)I_(6)Br_(3)(CBIB).Centimeter-size CBIB single crystal(Φ15×70 mm^(3))was grown by the vertical Bridgeman method.The powder X-ray diffraction analysis shows that CBIB has structure with lattice parameters of a=b=8.223Å,c=10.024Å,α=β=90°andγ=120°.The density functional theory(DFT)calculations demonstrate that the charge density distribution was enhanced after the dimensional expansion.The enhancement of carrier transport ability of(00l)in-plane is characterized before and after dimensional improvement.The obtained CBIB(001)exhibited an electron mobility up to 40.03 cm^(2)V^(−1)s^(−1)by time-of-flight(TOF)technique,higher than 26.46 cm^(2)V^(−1)s^(−1)of CBI(001).Furthermore,the X-ray sensitivity increases from 707.81μC Gy^(−1)cm^(−2)for CBI(001)to 3194.59μC Gy−1 cm^(−2)for CBIB(001).This research will deepen our understanding of Bi-based perovskite materials and afford more promising strategies for lead-free perovskite optoelectronic devices modification.
基金Project supported by the Ningxia College Scientific Research Project(NGY2017161)the National Natural Science Foundation of China(51342007,11864001,61461001)+4 种基金the National Key Basic Research Program(2011CB612310)the Ningxia First-class Discipline and Scientific Research Projects(Electronic Science and Technology,NXYLXK2017A07)Natural Science Foundation of Ningxia(NZ17104)the Key Research and Development Program of Ningxia Province(2018BEE03015)the Key Laboratory of North Minzu University(intelligent perception control)
文摘Bi_4 Si_3 O_(12):RE(BSO:RE, RE = Eu^(3+), Sm^(3+), Ho^(3+), Tb^(3+)) crystals were grown by the modified vertical Bridgeman method, and doping effects on scintillation properties were investigated. Under γ-ray irradiation, the light yield of BSO doped with small doses of Eu^(3+) increases slightly, and the energy resolution improves significantly compared to pure BSO, therefore the ability of distinguishing between particles will be improved for BSO crystals with a small amount of Eu^(3+) dopant. The results show that a small amount of Eu^(3+) doping can sensitize the Bi^(3+) ions. The sensitization effect enables the reduction of intrinsic defects, and thus improves the scintillation properties. However, the relative light yield of BSO:Tb(1.0 mol%) crystal is 4.3%, which is smaller than 5.0% of pure BSO. The improved light yield and energy resolution in the BSO:Eu and BSO:Sm crystals are considered an impressive achievement in the optimization of this scintillator which is already suitable for applications such as dual-readout calorimeters and homogeneous hadron calorimeters.
