重离子辐照SiO_2通过能量损失产生发光色心的研究  

Color Center Creation in SiO_2 Under Irradiation with Swift Heavy Ions: Dependence on Energy Loss

作　　者：宋银[1,2] 孟彦成[2] 张崇宏[2] 杨义涛[2] 李锦钰[2] 缑洁[2] 贺德衍[1] 

机构地区：[1]兰州大学物理科学与技术学院,甘肃兰州730000 [2]中国科学院近代物理研究所,甘肃兰州730000

出　　处：《发光学报》2012年第10期1049-1054,共6页Chinese Journal of Luminescence

基　　金：国家自然科学基金(10705037;10975165)资助项目

摘　　要：通过红外光谱和荧光发射光谱分别对600 keV、4 MeV和5 MeV Kr离子辐照的SiO2进行发光特性的研究。在低能量辐照体系中,简单色心(F2色心)的形成在损伤过程中占据主导地位,其主要诱发蓝光发射带;在高能离子辐照条件下,离子径迹上的能量密度较大,因此缺陷浓度的增大产生了一些缺陷团簇和离子径迹,形成了复杂的色心(F2+和F3+色心等)并诱发了强烈的绿光发射带和红光发射带。该实验结果与能量损失过程中统一热峰理论模型(一个综合的基于电子能损与核能损的非弹性碰撞模型和弹性碰撞模型)的模拟结果能够很好地吻合,表明在keV～MeV能区上存在电子能损过程与核能损过程的协同效应。SiO2 single crystals that irradiated with 600 keV,4 MeV and 5 MeV Kr ions were investigated in 320 kV high voltage Experimental Platform（IMP,Lanzhou） by infrared spectra and fluorescence spectroscopes.In the low-energy region,single ion tracks are well separated and the damage process is dominated by the formation of simple color centers such as F2 centers.For the high energy ions,the energy density in ion tracks produced at high stopping power is larger,and consequently the defect concentration increases significantly.At higher defect densities,the distance between single defects is smaller facilitating aggregation of individual electron centers to defect clusters and also defect annihilation by recombination of hole and electron centers.The latter process determines the limited efficiency of color-center creation under heavy-ion irradiation.Using the unified thermal spike model,it is possible to fully describe the experimental data,which clearly demonstrate a synergy between the nuclear energy loss and the electronic energy loss.

关 键 词：重离子辐照 色心发光 PL 热峰模型 

分 类 号：O469[理学—凝聚态物理]