Improving GaP Solar Cell Performance by Passivating the Surface Using AlxGa1-xP Epi-Layer

A good candidate for the top junction cell in a multi-junction solar cell system is the GaP solar cell because of its proper wide band gap. Here, for the first time, we passivate the front surface of these GaP solar cells with an AlGaP layer. To study the passivation effect of this layer, we design a novel growth procedure via liquid phase epitaxy. X-Ray diffraction results show that the resulting passivation epitaxial layer is of good quality. Integrated quantum efficiency measurements show an 18% increase in current due to the AlGaP. The current-voltage measurements indicate that with this AlGaP surface passivation layer, the GaP solar cell's efficiency is 2.90%. This is an improvement over previously reported results for GaP solar cells.