Generalized Weisskopf-Wigner Model of Triboelectroluminescence

The phenomenon of triboelectroluminescence is studied using a generalization of the Weisskopf-Wigner model of spontaneous emission in an electronic two-level system. An irreversible and exponential transfer of charge results from the model. The charge transfer between two linear atomic chains is computed as a function of the separation of the two chains and as a function of the temperature. Triboelectroluminescence due to spontaneous emission is found to be more efficient when the electron states in the two materials have a larger energy separation and decays rapidly with separation. It is insensitive to temperature variation when the electrons emanate from insulators or surface states, but not when they emanate from partially-filled bands due to the thermal excitation of the electrons.