Yb^(3+)/Er^(3+)共掺BaGd_2ZnO_5上转换发光动力学过程的研究  

Preparation and Up-Conversion Luminescence Dynamic Process of Yb^(3+)/Er^(3+) Co-Doped BaGd_2ZnO_5

作　　者：杨艳民[1] 焦福运[1] 苏红新[1] 李自强[1] 刘云峰[2] 李志强[1] 杨志平[1] 

机构地区：[1]河北大学物理科学与技术学院,河北保定071002 [2]河北大学工商学院,河北保定071002

出　　处：《光谱学与光谱分析》2012年第10期2637-2641,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(50902042);河北省自然科学基金项目(E2010000283);中国博士后科研基金项目(20100480840)资助

摘　　要：BaGd2ZnO5∶Yb3+,Er3+是目前报道的上转换效率最高的发光材料,有广泛的应用前景,但到目前为止还没有关于该基质材料中Er3+发光动力学过程研究的报道。采用溶胶凝胶法制备BaGd2ZnO5∶Yb3+,Er3+上转换发光材料,测量不同激发密度下上转换光发射功率及上转换效率。数据表明:当激发密度较低时,绿色光发射强度与激发光功率的二次方成正比;激发密度较高时,与激发光功率的一次方成正比;上转换能量效率先增大后减小,具有一个极大值。通过建立不同激发密度下,Er3+离子4 S3/2能级上转换光发射速率方程模型,阐述了产生这一现象的动力学过程和绿色光发射产生的机理。在弱激发条件下,用方波调制的971nm LD激光激发BaGd2ZnO5∶Yb3+,Er3+样品,测量上转换绿光的上升和衰减过程,用Er3+离子4 S3/2能级的速率方程拟合绿光的上升和衰减过程确定相关参数,证实Er3+离子4 S3/2能级粒子布居主要来自于Yb3+→Er3+的能量传递。Yb^3＋/Er^3＋ co-doped BaGd2 ZnO5 phosphors were prepared by using the sol-gel method. The up-conversion luminescence powers and efficiencies were measured under different excitation densities. The obtained data showed that the green luminescence power was proportional to the second-order of that of the excitation power under the lower excitation density and linearly in the higher one. The up-conversion mechanism under different excitation power was described by a rate equation. Yb^3＋/Er^3＋ co-doped BaGd2ZnO5 was excited by 971 nm LD laser with a square wave signal modulation and the rise and decay processes of green up-conversion luminescence were measured. In a low excitation condition, the rate equation of the energy level ^4S3/2 for Er^3＋ ions was used to fit the green rise and decay processes in order to fix the relevant parameters, and confirm that the population of ^4S3/2 energy level of Er^3＋ ion mainly came from the energy transfer from Yb^3＋＋to Er^3＋.

关 键 词：效率 上转换 速率方程 Yb^3+/Er^3+ 

分 类 号：O482.31[理学—固体物理]