Reduction of defects in GaP layers grown on Si(100) by MOCVD

Recent advances in III-V-on-Si heteroepitaxy have led to the demonstration of multi junction solar cells with improved photovoltaic conversion efficiencies. However, their performance is still limited by a high defect concentration at the GaP/Si(100) heterointerface and in the GaP buffer layer. In order to improve the crystal quality of the III-V layers, we substitute the pure GaP nucleation layer with GaP/AlP. The concentration and type of crystal defects in GaP buffer layers grown on different nucleation layers are investigated by electron chan-neling contrast imaging.