The decay of localized states into delocalized band states. Theory and preliminary experimental investigations using optically detected electron spin coherence

Abstract

A technique for measuring the decay of localized excited triplet states into the delocalized band states of a solid utilizing the optical detection of electron spin coherence is described. Specifically, the use of optically detected electron spin locking for measuring kinetic phenomena in the presence of fluctuating triplet spin sublevel populations is presented and illustrated. In addition, preliminary experimental data is reported which yields the temperature dependence of the phonon assisted promotion of a localized isotopic site to an energy equal to that associated with the energies of the host exciton band. Finally, the data is analyzed in terms of a kinetic model which relates the localized state's rate of promotion and radiationless decay into the exciton band states to explicit features of the exciton and phonon band structure.