Effect of the growth conditions on infrared upconversion efficiency of CaS: Eu, Sm thin films

Citation
Wh. Fan et al., Effect of the growth conditions on infrared upconversion efficiency of CaS: Eu, Sm thin films, APPL PHYS A, 73(1), 2001, pp. 115-119
Citations number
18
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
ISSN journal
0947-8396 → ACNP
Volume
73
Issue
1
Year of publication
2001
Pages
115 - 119
Database
ISI
SICI code
0947-8396(200107)73:1<115:EOTGCO>2.0.ZU;2-G
Abstract
High-quality electron-trapping thin films CaS: Eu, Sm with red light output have been successfully deposited on quartz and single-crystal silicon subs trates by electron beam evaporation (EBE) and radio frequency (RF) magnetro n sputtering in vacuum and H2S partial pressures. Infrared upconversion eff iciency of CaS: Eu, Sm thin films under different growth conditions has bee n investigated by using ultrashort infrared (IR) laser pulse with 20ps (ful l width at half-maximum (FWHM)). The results show that upconversion efficie ncy of CaS: Eu, Sm thin films depends strongly on growth conditions in spit e of the existence of "exhaustion" phenomena. Microstructures identified by X-ray diffraction (XRD) indicate that crystallinity of CaS films relies on both substrate materials and growth conditions. The stoichiometric composi tion of CaS films was measured by secondary-ion mass spectrometry (SIMS). T he post-annealing process was found to promote grain growth and activate st rong luminescence so that it could obviously improve upconversion efficienc y of CaS: Eu, Sm films, even though it had negative influence on transmitta nce and spatial resolution of these films.