Entropy production in photovoltaic conversion

Abstract

Recent experiments have shown that more than one electron-hole generation per photon in solar cells is possible. A number of modeling works to appraise the theoretical potential of cells with high quantum efficiency have been carried out by several authors, and in some of them violations of the thermodynamic principles have occurred. A procedure to test the thermodynamic coherence of ideal models is developed in this paper, and applied to the most convincing model so far presented, proving that it is thermodynamically coherent. For the purpose of demonstration, the procedure is applied to an alternative credible model that violates thermodynamics. Also in this paper the absolute thermodynamic limit of work production in light converters, beyond the reference to specific devices—so far studied for blackbody radiation—is proven for any kind of radiation.