Effect of interfacial AsH₃ surge treatment on GaInP/GaAs dual-junction solar cells grown by metal-organic vapor phase epitaxy

The effect of a modified PH₃-to-AsH₃ gas switching sequence with an AsH₃ surge treatment on GaInP/GaAs dual-junction solar cells was studied. With AsH3 surge treatment, both the material quality with an absence of defects and device performance was preserved, but without it, deterioration in both of these characteristics was observed, which originated in the As/P interface. It was found that defects with an inhomogeneous III-metal composition were formed at the interface and developed into a V-shaped dislocation which penetrated the GaInP top cell. The results suggest that sufficient arsenic supply is necessary prior to As-based material growth on GaInP.