Fluorescence spectra of Tm3+-doped rare earth oxychloride powder phosphors

This paper reports the fluorescence properties of a new family of Tm3+-doped powder phosphors of LaOCl, GdOCl, YOCl, (La,Gd)OCl, (La,Y)OCl and (Gd,Y)OCl. A bright blue emission (D-1(2) --> F-3(4)) was observed from all these phosphors under a UV lamp and this situation was confirmed by fitting the colour coordinates ((X) over bar, (Y) over bar) in the IEC chromaticity diagram. The relative fluorescence intensity ratios (R) for the different measured emission levels were also evaluated in order to examine the host matrix compositional effects on the fluorescence behaviours. For the measured fluorescent transitions, the stimulated emission cross sections (sigma(p)(E)) were also computed.