Wide Band Gap Gallium Phosphide Solar Cells

Gallium phosphide (GaP), with its wide band gap of 2.26 eV, is a good candidate for the top junction solar cell in a multijunction solar cell system. Here, we design, fabricate, characterize, and analyze GaP solar cells. Liquid phase epitaxy is used to grow the semiconductor layers. Four generations of GaP solar cells are developed and fabricated with each solar cell structure being designed and improved based on the first principles analyses of the predecessor solar cells. Quantum efficiency and current-voltage measurements are used to analyze the solar cell performance and to develop predictive models. We create a GaP solar cell with an efficiency of 2.42% under AM 1.5G one sun illumination.