Elektron-Gitter-Prozesse an Störstellen und ihre Darstellung im Konfigurationskoordinatendiagramm

Abstract

The spectral distribution of the F-center emission was measured and analysed between 5 and 167° K. From the temperature variation of its halfwidth the mean lattice frequency interacting with the excited F-state could be evaluated to 4.25. 10¹² sec⁻¹, which is by 40% higher than the corresponding value of the F ground state. With this value and the exact emission data the configurational coordinate model of the F-center could be constructed in a way, which is in quantitative agreement with absorption and emission properties at low temperature. The difference in the effective oszillator masses of the ground- and excited F-state, following from this model, is explained by the different symmetries of the lattice modes coupled to thes- andp-type electronic state.