English | NanjingTech | Contact
IAM星火大讲堂    
  科研信息   
  院务公告   
  学生事务   
  专题讲座   
  学术会议   
  IAM星火大讲堂   

当前位置: 通知公告 IAM星火大讲堂
IAM星火大讲堂第7期:意大利维罗纳大学化学与生物技术系Marco Bettinelli教授做客IAM星火大讲堂
阅读次数:650 添加时间:2016/11/5 发布: 管理员
二维码

扫描二维码,在手机中查看。

时 间:112514:00

地 点:科技创新大楼C501

报告人:Prof. Marco Bettinelli

报告题目:Tb3+-Eu3+ energy transfer in oxide materials

 

Abstract:

Despite numerous studies over the years, energy transfer processes are still interesting from both a fundamental and an applied point of view, as transfer processes in pairs of ions and from the host to luminescent ions are crucial for development of innovative phosphors, scintillators and materials for solar cells. Here I will present results on these processes, concentrating on the ion pairs Tb3+-Eu3+ in eulytite phosphate hosts.

Eulytite double phosphates A3M(PO4)3 (A=Ca, Sr, Ba; M=La-Lu, Y, Bi) are well known to be isotypic with the mineral eulytine (Bi4Si3O12). The emission spectrum of neat Sr3Tb(PO4)3 upon excitation at 337 nm in the levels above 5D3 is dominated by 5D4 emission; no significant emission from 5D3 is observed due to efficient cross relaxation involving the Tb3+ levels. On the other hand, the emission spectrum of the same host containing 10 mol% Eu3+ upon excitation at the same wavelength (in the Tb3+ levels) is dominated by strong emission bands from the 5D0 level of Eu3+. This indicates that Tb3+®Eu3+ energy transfer is clearly present. The excitation spectrum of the Eu3+ 5D0 emission is dominated by strong Tb3+ bands extending in the UV region.

The presence of 10% Eu3+ in Sr3Tb(PO4)3 very effectively shortens the 5D4 decay time from 2.68 to 0.20 ms. The decay curve is not far from exponential, indicating that the energy transfer to Eu3+ is accompanied by fast energy migration. The efficiency of the energy transfer from 5D4 amounts to 0.93, and the critical distance for the transfer from the 5D4 level of Tb3+ is about 7 ?.

The results obtained for the eulytite hosts will be compared with the ones recently obtained for double silicate hosts containing the same Tb3+ and Eu3+ ions.

 



Copyright © 2017-2019 南京工业大学先进材料研究院 All rights reserved. 官方微信
地址:南京市新模范马路5号138信箱   [旧版回顾]
电话: 025-83587982 邮件:iam@njtech.edu.cn