Group III element substitution effects on Eu-doped thiogallate phosphors

Photoluminescence properties of II-III2S4:Eu (II=Ca,Sr,Ba; III=Ga,In,Y,La; Eu concentration was 1 mol%) have been investigated systematically. In Ga compounds, well-known green∝yellow emissions are observed, while the emissions become very weak in In substituted compounds. In III=Y or La compounds, when II=Ca or Sr, red∝infrared emissions which seem to be due to phonon-terminated transition of the Eu2+ions are observed, while when II=Ba, strong sharp lines due to the Eu3+ions are detected. These spectral changes are discussed in terms of the effective ionic radii and the sulfur vacancies (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)