A 3-D model for concentrator solar cells based on distributed circuit units

A three-dimensional (3-D) distributed model for high-concentrator solar cells based on elementary units made up of electrical circuits is presented. The recombination mechanisms are dealt with in detail, paying special attention to the perimeter properties. No ohmic effect is omitted making this a powerful simulation tool for concentrator solar cells. A shunt resistance is also included. The model allows the simulation of the external connections and nonuniform illumination profiles making this model very useful for optimizing future structures and technological processes. The proposed 3-D model is compared with a lumped, two-diode model in the simulation of a GaAs solar cell operating from 1 to 2000 suns. It is found that the 3-D distributed model agrees satisfactorily with the experimental data for all concentrations. The agreement cannot be made simultaneously for both low and high concentrations for the lumped model.