Features of optoelectronic processes in a molecular junction based on a fluorophore with optically active Frontier π-orbitals: electrofluorochromism in a ZnPc-based junction.

A model of the optoelectronic process in a molecular junction has been developed, in which electron transfer occurs through transmission channels associated with the filling of the π and π* orbitals of the fluorophore with transferred electrons. The contribution of each channel to the formation of current and electroluminescence (EL) is determined by the probability of the realization of those electronic states of the molecule that, at a given bias voltage, are involved in electron transfer. It is shown that in the vicinity of critical bias voltage, stepwise changes in current and EL occur, and the height of each step is controlled by kinetic processes associated with both electron transfer and intramolecular transitions.