Stark Effects in <i>F</i> Center Emission in KBr, KI, RbBr, and RbI Crystals

Abstract

The Stark effects in F center emission have been investigated for KBr, KI, RbBr, and RbI crystals as a function of emission wave-length and polarization, electric field amplitude, and sample temperature, with using a PbS IR detector. Observed results are qualitatively similar to those measured by Bogan and Fitchen for several other alkali halides. The Stark polarization and the first moment change (a red shift) of the emission band are quadratic in electric field strength; their coefficients are tabulated. Two different theoretical forms of the temperature dependence of the Stark polarization P ( T ), which have been derived by Bogan and Fitchen, and Ham and Grevsmühl, respectively, are found to be invalid to explain the experimental data consistently. A phenomenological form to describe P ( T ) is proposed by introducing a new parameter.