PL studies of Ce³⁺‐ and Pr³⁺‐doped SrS thin films

Abstract

Abstract— Both time‐resolved and steady‐state spectroscopic techniques were used to investigate the mechanisms responsible for both the observed increase in luminance and the red shift of the emission frequency that occurs when Ga is introduced during the growth of SrS: Ce3+ films. We compared the excitation spectra of SrS: Ce3+ films prepared without Ga to SrS: Ce3+ and SrS: Pr3+,Ce3+ films prepared with Ga. In addition, we also studied praseodymium‐doped thin films to probe the local environment of the rare‐earth ion in these materials. Finally, the implications of these results on the electroluminescent (EL) efficiency will be discussed.

Luminescence and Energy Transfer in Thin Films of SrGa2 S 4 : Ce

“…The time constants for the initial decay of Ce 3ϩ luminescence in a series of SrGa 2 S 4 :Ce increased gradually from 60 to 85 ns with increasing activator concentration from 0.2 to 6 mol %. These values are close to the previous estimates reported by Peters 18 and Evans and colleagues 19 for Ce-activated thiogallates. However, these time constants are considerably longer than those reported by Hoshina 11 and more recently by Fouassier and Garcia for SrGa 2 S 4 :Ce powder samples.…”