Luminescence and electrical conductivity of crystal phosphors

Using a general form of the energy band model for a crystal with a wide distribution of lattice defect levels, comprehensive equations are developed which relate the luminescence and photoconduction in crystal phosphors to excitation intensity, time and temperature for different physical conditions. These include steady state excitation, phosphorescence, photoconduction decay and continuous warming of the phosphor. Measurements on single crystals of ZnS and CdS show good agreement between the theory and experiment.