The effect of site occupation and valence state of Bi on the luminescence properties of Bi-activated oxysulfide MZnOS (M = Ca, Ba) with layer structure

A novel blue-green-emitting and red-emitting phosphor MZnOS: Bi, Li (M = Ca, Ba) have been prepared, and the correlation between site occupation, valence state of Bi in MZnOS and their luminescence properties was investigated. In MZnOS, M sites are the most suitable and stable sites for Bi to occupy according to the Rietveld refinement and first principle calculation. Bi is found to be in trivalent state in CaZnOS, but is a mixture of divalent …