Effect of H_2S annealing for low energy cathodoluminescence of blue-emitting SrGa_2S_4 : Ce thin films

Abstract

Ce^<3+>-doped strontium thiogallate (SrGa_2S_4 : Ce) thin films which show blue emission have been prepared by multi-source deposition (MSD). Sr metal, Ga_2S_3 and CeCl_3 powders were used as source materials. It was found that the annealing in H_2S atmosphere was considerably effective for the improvement of the crystallinity and luminescent properties of the SrGa_2S_4 : Ce films. When the films deposited at a substrate temperature or 450℃ were annealed at 800℃ for 1〜2 hours in H_2S atmosphere, the improvement of cathodoluminescent intensity larger than 50 times was accomplished. Moreover, the films showed blue emission with the CIE coordinates of (0.12,0.10).