摻雜 Er3+ 離子於 Gd2Ti2O7 奈米粉體與薄膜之上轉換螢光特性之研究

A Study on Up-converted Luminescence Properties of Er3+-doped Gd2Ti2O7 Nanocrystals and Films.

李御賓(Yu-Ping Li)

指導教授 ： 丁初稷

國立中正大學/工學院/光機電整合工程研究所/碩士(2014年)

摘要

本論文旨在研究改變不同的摻雜濃度與製程溫度來合成Er3+-doped Gd2Ti2O7粉末與薄膜，並探討其螢光特性、薄膜特性。
我們使用溶膠-凝膠法製備Er3+ (5, 10, 15, 20 mol%)-doped Gd2Ti2O7奈米粉末，在980 nm雷射激發下得知其在Er3+ (10 mol%)–doped Gd2Ti2O7 粉末在退火溫度超過800℃後，具有下與上轉換發光特性，其發光峰值分別為405 nm (2H9/2→4I15/2)、520 nm (4H11/2→4I15/2)、545 nm (4S3/2→4I15/2)、650 nm (4F9/2→4I15/2)、1534 nm ( 4I13/2→4I15/2)。且由XRD繞射圖的結果得知具有良好的結晶特性，其平均結晶顆粒大小在 SEM 觀察下可發現隨著退火溫度的提高 (800~1200 ℃) 而從~80 nm增加到~200 nm。
我們在Er3+ (0, 10, 20, 100 mol%)-doped Gd2Ti2O7薄膜在不同的摻雜濃度和製程溫度下，研究其薄膜的光學性質與其成膜後的表面粗糙度，再選擇以spin-coating 的方式將溶膠狀的螢光粉塗佈在玻璃基板後，發現其平均粗糙度都在 0.1 nm~0.214 nm 間，並以包絡線之方法求得光學薄膜之常數(折射率、光學能隙、堆積密度)與製程溫度和摻雜濃度的關係。

關鍵字

上轉換

並列摘要

The purpose of this paper is to change the different doping concentration and the process temperature to synthesize of Er3+-doped Gd2Ti2O7 powders and films, and to explore its fluorescence properties　and characteristics of thin films.
Er3+-doped Gd2Ti2O7 nanocrystals were fabricated by the sol-gel method.Under the 980 nm laser excitation of the Er3+ (10 mol%) – doped Gd2Ti2O7 powder with annealing more than 800 ℃ can produce the up-conversion (405, 520, 545, and 650 nm; 2H9/2→4I15/2, 4H11/2→4I15/2, 4S3/2→4I15/2 and 4F9/2→4I15/2, respectively) and Stokes luminescence (1534 nm; 4I13/2→4I15/2).And the XRD shows that while the annealing temperature exceeds 800 °C, amorphous pyrochlore phase Er3+-doped Gd2Ti2O7 transfers to well-crystallized nanocrystals. The average crystal size can be observed by SEM that it increases from 80 nm to 200nm while the annealing temperature increases from 800 to 1200 °C for an hour.
We discuss optical properties and roughness of the Er3+ (0, 10, 20, 100 mol%)-doped Gd2Ti2O7film in different concentration and processing temperature.And then we coat colloidal phosphor on the glasses by spin coating. It is found that the average roughness is at 0.1 nm to 0.214 nm, and we use the method (by R.Swanepoel) to obtain the relations of film refractive index, optical band gap and packing density between the process temperature and doping concentration.

並列關鍵字

up conversion

參考文獻

[3] Pang M L, Lin J , Fu J , Cheng Z Y., Mater. Res. Bull., 2004 , 39: 1607.

[4] Zhang F X, Saxena S K., Chem. Phys. Lett. , 2005 ,413 , 248.

[8] C. Feldmann, T. Jüstel, C. R. Ronda and P. J. Schmidt, Adv. Funct. Mater. 13 (2003) 511

[9] J. A. DeLuca, J. Chem. Edu. 57 (1980) 541.

[10] A. H. Kitai, “Solid state luminescence”, Chapman & Hall, Inc., UK, 1993, p. 30.