Photoluminescence and X-Ray Diffraction Properties of Europium and Silver Co-Doped Tantalum-Oxide Thin Films Deposited by Co-Sputtering

Keisuke Shimada,Kenta Miura,Masahiro Kanakubo,Osamu Hanaizumi,Ryosuke Fujii,Wataru Kada

doi:10.4236/msce.2017.52004

Abstract

We fabricated europium and silver co-doped tantalum-oxide (Ta2O5:Eu, Ag) thin films using a simple co-sputtering method for the first time, and we evaluated their photoluminescence (PL) and X-ray diffraction (XRD) properties. We found that the most remarkable PL peak at a wavelength of 615 nm due to Eu3+ can be enhanced by Ag doping, and the strongest PL peak can be obtained from a Ta2O5:Eu, Ag thin film after annealing at 1000℃. Based on XRD measurements, we found that Ag2Ta8O21 crystalline phases produced by Ag doping are very important and Eu3TaO7 phases should be avoided in order to enhance the objective PL peak from our Ta2O5:Eu, Ag thin films.

Highlights

Tantalum pentoxide (Ta2O5) is a high-refractive-index, stable material widely used in passive optical elements such as Ta2O5/SiO2 multilayered wavelength filters for dense wavelength-division multiplexing (DWDM)
Based on X-ray diffraction (XRD) measurements, we found that Ag2Ta8O21 crystalline phases produced by Ag doping are very important and Eu3TaO7 phases should be avoided in order to enhance the objective PL peak from our Ta2O5:Eu, Ag thin films
It seems that the above-mentioned Ag2Ta8O21 crystalline phases produced by Ag doping should exist and the Eu3TaO7 phases should be avoided in order to enhance the objective PL peak from the film

Summary

Introduction

Tantalum pentoxide (Ta2O5) is a high-refractive-index, stable material widely used in passive optical elements such as Ta2O5/SiO2 multilayered wavelength filters for dense wavelength-division multiplexing (DWDM). It has been used as a high-index material of Ta2O5/SiO2 multilayered photonic-crystal elements for the visible to near-infrared range fabricated using radio-frequency (RF) bias sputtering [1] [2]. Dousti et al reported that luminescence from erbium (Er)-doped tellurite glasses can be enhanced by silver (Ag) co-doping [10] In this short report, we will present the first fabrication of Eu and Ag co-doped Ta2O5 (Ta2O5: Eu, Ag) thin films using our co-sputtering method and the first observation of the enhanced PL from the films. We will discuss the relationship between their PL properties and crystallizability

Preparation

Evaluation

Results and Discussion

Conclusion