本文采用第一性原理对纯Al2O3和Si掺杂的Si0.167Al0.833O1.5,Si0.25Al0.75O1.5晶体体系的能带结构、态密度进行了计算分析.结果发现:随着Si在Al2O3晶体中所占比例的增加,体系能隙变小,在Si0.25Al0.75O1.5晶体体系中能隙已降到2.5 e V,...本文采用第一性原理对纯Al2O3和Si掺杂的Si0.167Al0.833O1.5,Si0.25Al0.75O1.5晶体体系的能带结构、态密度进行了计算分析.结果发现:随着Si在Al2O3晶体中所占比例的增加,体系能隙变小,在Si0.25Al0.75O1.5晶体体系中能隙已降到2.5 e V,表明该体系为半导体材料;而在掺杂的体系中有数条分散的能带穿过了费米能级,即可以预测该掺杂体系有特别的光电性质;同时对比纯Al2O3和Si掺杂的Si0.167Al0.833O1.5,Si0.25Al0.75O1.5晶体体系的总态密度,发现掺杂体系的价带和导带向低能区域移动.展开更多
Si4+-doped BaZr(BO3)2:Eu3+ phosphors are prepared by a conventional solid-state reaction.The influence of Si4+ addition on the charge transfer state of Eu3+-O2- and photoluminescence(PL) properties of BaZr(BO3)2:Eu3+ ...Si4+-doped BaZr(BO3)2:Eu3+ phosphors are prepared by a conventional solid-state reaction.The influence of Si4+ addition on the charge transfer state of Eu3+-O2- and photoluminescence(PL) properties of BaZr(BO3)2:Eu3+ are discussed.Room temperature PL spectra indicated that efficient emission is obtained by Si doping.Increased values for the peak-peak ratio(PPR) of BaZr(BO3)2:Eu3+ at higher Si doping concentrations implied that the Eu3+ ion is located in a more asymmetric environment in BaZr0.8Si0.2(BO3)2:Eu3+ than in the undoped samples.The Judd-Ofelt parameters Ωλ(λ=2,4) were calculated from the PL data,giving results that were consistent with those from the PPR.The maximum radiative quantum efficiency was achieved at a Si doping concentration of 20 mol%.展开更多
文摘本文采用第一性原理对纯Al2O3和Si掺杂的Si0.167Al0.833O1.5,Si0.25Al0.75O1.5晶体体系的能带结构、态密度进行了计算分析.结果发现:随着Si在Al2O3晶体中所占比例的增加,体系能隙变小,在Si0.25Al0.75O1.5晶体体系中能隙已降到2.5 e V,表明该体系为半导体材料;而在掺杂的体系中有数条分散的能带穿过了费米能级,即可以预测该掺杂体系有特别的光电性质;同时对比纯Al2O3和Si掺杂的Si0.167Al0.833O1.5,Si0.25Al0.75O1.5晶体体系的总态密度,发现掺杂体系的价带和导带向低能区域移动.
基金supported by the National Basic Research Program of ChinaNational Natural Science Foundation of China (60877029, 60977035, 60907021)+1 种基金Natural Science Foundation of Tianjin Education Committee (20071207)Natural Science Foundation of Tianjin (09JCYBJC01400, 07JCYBJC06400)
文摘Si4+-doped BaZr(BO3)2:Eu3+ phosphors are prepared by a conventional solid-state reaction.The influence of Si4+ addition on the charge transfer state of Eu3+-O2- and photoluminescence(PL) properties of BaZr(BO3)2:Eu3+ are discussed.Room temperature PL spectra indicated that efficient emission is obtained by Si doping.Increased values for the peak-peak ratio(PPR) of BaZr(BO3)2:Eu3+ at higher Si doping concentrations implied that the Eu3+ ion is located in a more asymmetric environment in BaZr0.8Si0.2(BO3)2:Eu3+ than in the undoped samples.The Judd-Ofelt parameters Ωλ(λ=2,4) were calculated from the PL data,giving results that were consistent with those from the PPR.The maximum radiative quantum efficiency was achieved at a Si doping concentration of 20 mol%.
基金Project supported by the National Natural Science Foundation of China(No.20671028)Natural Science Foundation of Hebei Province(No.E2006000172)the Science Foundation of Post Doctor of China(No.2005038511)
