STATISTICAL THERMODYNAMIC FOUNDATION FOR PHOTOVOLTAIC AND PHOTOTHERMAL CONVERSION .1. THEORY

We intend to cover the need for a general statistical foundation of the thermodynamic models of photovoltaic and/or photothermal conversion. The solid body receiving radiation is considered in considerable generality. This includes (1) nuclei of the lattice and their core electrons, (2) the electrons of the conduction band, (3) the electrons or holes of the valence band, (4) the traps in the forbidden gap. These components are subject to radiation and external fields (such as mechanical stress, gradients of electrostatic potential, or of temperature). The basis of the treatment is the Boltzmann transport equation. Different forms of this equation are considered, as the particles encountered in the body receiving radiation are both fermions (electrons and holes) and bosons (photons and phonons). Three main directions are followed. First, the continuity equations are derived in a rigorous manner. Second, the irreversibilities occurring during the conversion of radiation are emphasized. Third, the differences and similarities between photovoltaic and photothermal conversion are investigated. (C) 1995 American Institute of Physics.