EXCITATION AND FLUORESCENCE-SPECTRA IN CA1-XCDXS SOLID-SOLUTIONS

Ca1-xCdxS solid solutions have been prepared at a slight excess sulphur pressure in a nitrogen atmosphere at 1025-degrees-C. Solid solutions up to x = 0.40 have been observed in samples treated under these conditions for two hours. The lattice parameter is found to vary linearly with composition in line with predicted unit cell dimensions. Excitation spectra indicate that for x = 0.01 and 0.10 at 77 K very intense emissions in the blue/violet are observed for excitation at 300 nm and for x = 0.01 at 300 K in the blue. The fluorescence emission intensity in samples with x = 0.31 and 0.40 is enhanced by an increasing presence of a CdS phase emitting in the green at 500 nm.