ABSTRACT
This chapter develops a detailed study of the photovoltage that can be obtained in a solar cell, with particular attention to the maximal photovoltage in the limit of pure radiative recombination, and investigates the causes for a reduced photovoltage. It describes the physical constraints of the phenomenon of luminescent refrigeration based on the fact that the radiative emission of a biased semiconductor can be applied to remove heat in the form of photons. The chapter discusses the application of the reciprocity relation on an organic solar cell where light absorption is associated with the CT between different materials. It examines the open-circuit voltage, which is the voltage produced autonomously by the solar cell when it is irradiated with light. The open-circuit voltage is rather easy to measure and it is a main performance parameter of a solar cell.
