Field-dependence of the optical band gap in CdO-P₂O₅glass

Abstract

Photoconduction measurements have been made on cadmium phosphate glass with composition 50 mol% CdO and 50 mol% P2O5. At various fields, the values of energy band gap have boon deduced from the spectral dependence curves. The optical band gap obtained from these measurements shows a slow decrease with increasing fields. When extrapolated to zero field, a value of 5.16 eV is obtained for the optical band gap. This value is higher than the reported band gap obtained by absorption measurements on the same material. This difference is discussed.