Passivation of dislocations in GaAs grown on Si substrates by phosphine (PH3) plasma exposure

The phosphidization effect on dislocations in GaAs grown on Si substrate (GaAs/Si) has been investigated. It was found that the high density of dislocations in GaAs/Si heteroepitaxial layers largely enhanced the diffusion of phosphorus (P) atoms during the phosphine (PH3) plasma exposure. The incorporated P atoms strongly passivated the electrical states of residual dislocations in GaAs/Si solar cell. As a result, the PH3 plasma exposure largely increased the open circuit voltage (Voc) and the efficiency of GaAs/Si solar cell.