A quantum open system model of molecular battery charged by excitons.

The analytically tractable model employing quantum Markovian master equations, derived by a weak coupling procedure and generating completely positive dynamics is proposed to describe a model of a molecular battery charged by a nonequilibrium excitonic reservoir. Excitons are produced by nonequilibrium processes involving, e.g., light absorption and chemical reactions. Various relations concerning the efficiency of the involved processes of energy transfer and the stability of the battery are discussed. The model can be treated as an initial step in applications of a mathematically sound version of quantum theory of open systems to complex processes of energy transfer in biological systems and man-made devices based on organic materials.