Front contact grid optimization of III-V solar cells with SPICE network simulation

A distributed network model for the optimization of the front contact grid structure has been developed. By dividing the solar cell into small elementary cells the model includes distributed series resistance effects. With this approach it is possible to simulate the complete solar cell with grid fingers, busbars and nonpassivated sides of the solar cell. The accuracy of the simulation was verified through a comparison between measurement and simulation of Gallium Arsenide (GaAs) solar cells with different finger spacing and finger lengths. The developed tool is applied to analyze the optimum contact grid and solar cell size for various concentrations. In addition, the global efficiency maximum of a GaAs solar cell was identified to be 29.1 % at 450 suns with a designated area of 1 mm².