Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403


공학

한국표면공학회지 (55권2호 96-101)

Structural, optical, and morphological properties of BaWO4:Sm3+ phosphor thin films grown at different deposition temperature

서로 다른 증착 온도에서 성장된 BaWO4:Sm3+ 형광체 박막의 구조, 광학, 표면 형상의 특성

조신호*
Shinho Cho*

신라대학교 신소재공학과
Department of Materials Science and Engineering, Silla University, Busan 46958, Korea

DOI : 10.5695/JSSE.2022.55.2.96

Abstract

The effects of the growth temperature on the structural, optical, and morphological properties of BaWO4:Sm3+ phosphor thin films were investigated. The BaWO4:Sm3+ thin films were grown on quartz substrates at several growth temperatures by radio-frequency magnetron sputtering. All the thin films crystallized in a tetragonal structure with a main BaWO4 (112) diffraction peak. The 830 nm-thick BaWO4:Sm3+ thin films grown at 300 ℃ exhibited numerous polygon-shaped particles. The excitation spectra of BaWO4:Sm3+ thin films consisted of a broad excitation band in the 200–270 nm with a maximum at 236 nm due to the O2--Sm3+ charge transfer and two small bands peaked at 402 and 463 nm, respectively. Under 236 nm excitation, the BaWO4:Sm3+ thin films showed an intense red emission peak at 641 nm due to the 4G5/2→6H9/2 transition of Sm3+, indicating that the Sm3+ ions occupied sites of non-inversion symmetry in the BaWO4 host lattice. The highest emission intensity was observed for the thin film grown at 300 ℃, with a 51.8% transmittance and 5.09 eV bandgap. The average optical transmittance in the wavelength range of 500–1100 nm was increased from 53.2% at 200 ℃ to 60.8% after growing at 400 ℃. These results suggest that 300 ℃ is the optimum temperature for growing red-emitting BaWO4:Sm3+ thin films.

Keywords

Thin Film, Photoluminescence, Growth temperature