Ln_2Sn_2O_7∶Er^(3+)纳米晶的制备及发光性能研究  

Preparation and Up-conversion Emissions of Er^(3+) Doped Ln_2Sn_2O_7 Nanocrystals

作　　者：陈菊[1] 丁玲红[1] 张伟风[1] 

机构地区：[1]河南大学物理与电子学院光伏材料省重点实验室,河南开封475004

出　　处：《发光学报》2013年第11期1451-1456,共6页Chinese Journal of Luminescence

基　　金：河南省高校科技创新团队计划(2012 IRTSTHN0004)资助项目

摘　　要：采用溶胶-凝胶法合成Ln2Sn2O7∶Er3+(Ln=La,Gd,Y)纳米晶。通过X射线衍射和场发射扫描电子显微镜测试了样品的晶体结构和形貌,同时对样品的上转换发光性能进行了测试。结果表明:在980 nm连续激发光的激发下,样品主要表现为绿光发射。发射中心在528,549 nm的绿光和672 nm处的红光发射分别对应Er3+离子的4S3/2→4I15/2、2H11/2→4I15/2和4F9/2→4I15/2跃迁。以La2Sn2O7∶Er3+纳米晶为例,Er3+离子的摩尔分数为7%、退火温度为1 150℃是其制备的最佳条件,此时其各个发射峰的强度最高。对La2Sn2O7∶Er3+的发光强度与激发功率关系的研究表明,其绿光和红光发射均为双光子过程。激发光吸收和能量转移是La2Sn2O7∶Er3+纳米晶上转换发光的主要机制。Er3 +doped Ln2Sn2O7( Ln = La,Gd,Y) nanocrystals were fabricated by sol-gel method.The crystal structure and morphologies were investigated by XRD and SEM,and the up-conversion spectroscopic properties of the samples were also investigated. Under the excitation of a 980 nm diode laser,the samples mainly emit bright green light. The strong green and red up-conversion emissions which centered at 549,528,and 672 nm,respectively. They were assigned to the transitions of2H11 /2→4I15 /2,4S3 /2→4I15 /2and4F9 /2→4I15 /2energy levels of Er3 +ions. Taking La2Sn2O7∶Er3 +nanocrystal for example,the most efficient up-conversion emission can be obtained when the annealing temperature is 1 150 ℃ and the mole fraction of Er3 +is 7%. The dependence of the intensity of up-conversion emissions upon the excitation power of the diode laser suggests that twophoton absorption processes are involved in the green and red up-conversion luminescence. The excited state absorption and energy transfer process are regarded as the main up-conversion emission mechanism of La2Sn2O7∶ Er3 +nanocrystals.

关 键 词：上转换 溶胶-凝胶法 稀土锡酸镧 烧绿石 

分 类 号：O482.31[理学—固体物理]