Green nanophosphors(Gd,Y)PO4:Tb were prepared by solid state chemical reaction of precursors at room temperature.The formation process,particle-size,shape and fluorescence properties of the phosphor were characterized...Green nanophosphors(Gd,Y)PO4:Tb were prepared by solid state chemical reaction of precursors at room temperature.The formation process,particle-size,shape and fluorescence properties of the phosphor were characterized by means of XRD,TEM and solid fluorescence techniques.The results indicate the nanophosphor of(Gd,Y)PO4:Tb belong to the monoclinic system,its space group is P21/ n,its average particle size is 35nm,has better particle dispersion.The phosphor exhibits green fluorescence when excited by ultraviolet radiation of 380nm wavelength.The strongest peak is at 545nm,which assigned to 5D4→7F5 transition of Tb3+ ion.The phosphor is a kind of efficient green-emitting luminescence material.展开更多
卤化铅钙钛矿具有高光吸收系数、长载流子扩散长度和高荧光量子效率等优异光电特性,成为当下光电探测器(PDs)研究领域的热点。但卤化铅钙钛矿的高生物毒性和低环境稳定性制约了该类器件的发展和应用,因此寻找低毒稳定的材料尤为重要。...卤化铅钙钛矿具有高光吸收系数、长载流子扩散长度和高荧光量子效率等优异光电特性,成为当下光电探测器(PDs)研究领域的热点。但卤化铅钙钛矿的高生物毒性和低环境稳定性制约了该类器件的发展和应用,因此寻找低毒稳定的材料尤为重要。到目前为止,Sn、Ge、Sb、Bi等材料都已得到研究,其中铋基钙钛矿因其稳定、无毒和宽带隙等特性成为候选材料之一。影响PDs性能的因素很多,其中抑制暗电流是提升器件性能的重要手段之一。本文通过溶液旋涂无机化合物CuSCN取代传统PEDOT∶PSS作为空穴传输层(HTL),制备了结构为ITO/CuSCN/Cs_(3)Bi_(2)I_(6)Br_(3)/Zn O/Ag的p-i-n型光电探测器。CuSCN最低未占分子轨道(LUMO)能级为-1.5 e V,与ITO电子注入势垒高达3.3 e V,远高于PEDOT∶PSS与ITO的电子注入势垒(1.8 e V),反向偏压下工作更能有效阻挡电子从ITO电极的注入,因此降低了探测器的暗电流。器件在自供电条件425 nm单色光照射下光电流达6.87×10^(-6)A,暗电流低至3.52×10^(-11)A,开关比超过10~5,相比于基于PEDOT∶PSS空穴传输层的探测器提升了2个数量级。此外,该探测器的上升和下降时间都小于0.12 s,均优于基于PEDOT∶PSS空穴传输层的探测器,这可归因于CuSCN比PEDOT∶PSS具有更高的载流子传输迁移率。结果表明,ITO/CuSCN/Cs_(3)Bi_(2)I_(6)Br_(3)/Zn O/Ag结构的光电探测器具有自供电、高开关比、稳定、无毒等优点,为实现商业化提供了一种可行策略。展开更多
文摘Green nanophosphors(Gd,Y)PO4:Tb were prepared by solid state chemical reaction of precursors at room temperature.The formation process,particle-size,shape and fluorescence properties of the phosphor were characterized by means of XRD,TEM and solid fluorescence techniques.The results indicate the nanophosphor of(Gd,Y)PO4:Tb belong to the monoclinic system,its space group is P21/ n,its average particle size is 35nm,has better particle dispersion.The phosphor exhibits green fluorescence when excited by ultraviolet radiation of 380nm wavelength.The strongest peak is at 545nm,which assigned to 5D4→7F5 transition of Tb3+ ion.The phosphor is a kind of efficient green-emitting luminescence material.
文摘卤化铅钙钛矿具有高光吸收系数、长载流子扩散长度和高荧光量子效率等优异光电特性,成为当下光电探测器(PDs)研究领域的热点。但卤化铅钙钛矿的高生物毒性和低环境稳定性制约了该类器件的发展和应用,因此寻找低毒稳定的材料尤为重要。到目前为止,Sn、Ge、Sb、Bi等材料都已得到研究,其中铋基钙钛矿因其稳定、无毒和宽带隙等特性成为候选材料之一。影响PDs性能的因素很多,其中抑制暗电流是提升器件性能的重要手段之一。本文通过溶液旋涂无机化合物CuSCN取代传统PEDOT∶PSS作为空穴传输层(HTL),制备了结构为ITO/CuSCN/Cs_(3)Bi_(2)I_(6)Br_(3)/Zn O/Ag的p-i-n型光电探测器。CuSCN最低未占分子轨道(LUMO)能级为-1.5 e V,与ITO电子注入势垒高达3.3 e V,远高于PEDOT∶PSS与ITO的电子注入势垒(1.8 e V),反向偏压下工作更能有效阻挡电子从ITO电极的注入,因此降低了探测器的暗电流。器件在自供电条件425 nm单色光照射下光电流达6.87×10^(-6)A,暗电流低至3.52×10^(-11)A,开关比超过10~5,相比于基于PEDOT∶PSS空穴传输层的探测器提升了2个数量级。此外,该探测器的上升和下降时间都小于0.12 s,均优于基于PEDOT∶PSS空穴传输层的探测器,这可归因于CuSCN比PEDOT∶PSS具有更高的载流子传输迁移率。结果表明,ITO/CuSCN/Cs_(3)Bi_(2)I_(6)Br_(3)/Zn O/Ag结构的光电探测器具有自供电、高开关比、稳定、无毒等优点,为实现商业化提供了一种可行策略。
