Change in Structure of Blue and Green Fluorescence in Cadmium Sulfide at Low Temperatures

The two fundamental fluorescences observed in cadmium sulfide crystals subjected to ultraviolet excitation at low temperatures are classified according to wavelength. Photographs of the two fluorescences at 4.2^∘{}K and 77^∘{}K are given, and their structures are compared. Experimental evidence on the change in structure of the green emission near 5130A between 4.2^∘{}K and 77^∘{}K is presented and used to confirm an explanation for the apparent "green" shift in cadmium sulfide proposed by D. G. Thomas and J. J. Hopfield.