采用基于密度泛函理论的相对论性离散变分和嵌入团簇方法,计算了掺钇PbWO4晶体中多种相关缺陷的电荷分布和不同团簇缺陷结合能,并讨论了相关缺陷的电荷补偿机制.VPb是掺Y钨酸铅晶体中主要的电荷补偿方式.YPb3++VPb相关缺陷可能是晶体中存在的主要缺陷,其中[2(Y3+Pb)-VPb'']在晶体中更稳定.缺陷态[2(Y3+Pb)-VPb'']和[(Y3+Pb)-VPb'']的态密度分布及其激发能的计算结果表明:掺Y晶体O2p→W5d的跃迁能量均为4.3eV,使周围WO42-禁带宽度增大,可改善420nm与350nm的吸收,并通过减少VPb-VO联合空位可有效抑制PbWO4晶体的本征吸收.晶体中掺Y与掺La对发光影响不同,掺Y可敏化PWO晶体的蓝发光.
参考文献
| [1] | Lecoq P.;Auffray E.;Schneegans M.;Korzhik MV.;Missevitch OV.;Pavlenko VB.;Fedorov AA.;Annenkov AN.;Kostylev VL.;Ligun VD.;Dafinei I. .LEAD TUNGSTATE (PBWO4) SCINTILLATORS FOR LHC EM CALORIMETRY[J].Nuclear Instruments and Methods in Physics Research, Section A. Accelerators, Spectrometers, Detectors and Associated Equipment,1995(2/3):291-298. |
| [2] | Kobayashi M.;Ishii M.;Yazawa T.;Hara K.;Tanaka M.;Nikl M. Nitsch K.;Usuki Y. .IMPROVEMENT IN TRANSMITTANCE AND DECAY TIME OF PBWO4 SCINTILLATING CRYSTALS BY LA-DOPING[J].Nuclear Instruments and Methods in Physics Research, Section A. Accelerators, Spectrometers, Detectors and Associated Equipment,1997(2/3):261-268. |
| [3] | Kobayashi M.;Ishii M.;Yazawa T.;Hara K.;Tanaka M.;Nikl M. Baccaro S.;Cecilia A.;Diemoz M.;Usuki Y. .Improvement in radiation hardness of PbWO4 scintillating crystals by La-doping[J].Nuclear Instruments and Methods in Physics Research, Section A. Accelerators, Spectrometers, Detectors and Associated Equipment,1998(1):149-156. |
| [4] | Kobayashi M.Radiation Hardness of Doped PbWO4[A].in August,1999 |
| [5] | Li J Z.Improvement in Scintillation Properties of PbWO4 Crystals by the Point View of Defect[A].in August,1999 |
| [6] | Yin Z W.On Mechanism of Radiation Hardness in PbWO4 Crystals by the Point View of Defect[A].,1999 |
| [7] | Auffray E.;Korzhik M.;Annenkov A.;Jarolimek O.;Nikl M. Baccaro S.;Cecilia A.;Diemoz M.;Dafinei I.;Lecoq P. .Improvement of several properties of lead tungstate crystals with different doping ions[J].Nuclear Instruments and Methods in Physics Research, Section A. Accelerators, Spectrometers, Detectors and Associated Equipment,1998(1):75-84. |
| [8] | Shi C S.On the Green Emission Centers on PbWO4 Scintillator[A].in August,1999 |
| [9] | 刘波,施朝淑,魏亚光,吴灿,李裕熊,胡关钦,沈定中.掺Y对PbWO4闪烁体的热释光影响[J].物理学报,2000(10):2078-2082. |
| [10] | Huang H W .Impedence Spectroscopy Analysis of Doped PbWO4 Single Crystals[J].Phys Stat,2001,A187:2563. |
| [11] | Lin QS.;Feng XQ. .Computer simulation study of extrinsic defects in PbWO4 crystals[J].Journal of Physics. Condensed Matter,2003(12):1963-1973. |
| [12] | Li W S;Tand T B et al.Doping Mechanisms of La, Y and Excess Oxygen inPbWO4[J].Japanese Journal of Applied Physics,2001,40:1-4. |
| [13] | Ceperley D M;A lder B J .Ground State of the Electron Gas by a Stochastic Method[J].Physical Review Letters,1980,45:566. |
| [14] | 林奇生 .钨酸铅闪烁晶体的微结构研究[D].中国科学院上海硅酸盐研究所,2001. |
| [15] | ELLIS D E;Guo J.Electronic Density Functional Theory of Molecules, Clusters, and Solids[M].,1995:263. |
| [16] | 徐光宪.量子化学基础理论和从头计算法[M].北京:科学出版社,1999:1075. |
| [17] | 童宏勇 等.钨酸铅电子结构的密度泛函[J].计算物理,2000,49:1545. |
| [18] | 姚明珍,顾牧,梁玲,段勇,马晓辉.PbWO4晶体空位型缺陷电子结构的研究[J].物理学报,2002(01):125-128. |
| [19] | 童宏勇 .钨酸铅晶体及其缺陷电子结构的研究[D].上海:同济大学,2001. |
| [20] | 姚明珍,顾牡.掺镧钨酸铅晶体缺陷的理论研究[J].人工晶体学报,2002(05):460-463. |
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