Current-voltage characteristics of p-GaAs∕n-GaN heterojunction fabricated by wafer bonding

p-GaAs∕n-GaN heterojunction was fabricated by wafer bonding. Its current-voltage characteristic was systematically investigated at room temperature and at a variety of low temperature. The curves of different temperatures in the logarithmic scales indicate space-charge-limited currents (SCLCs) in the high voltage region (>0.4V). SCLC current-transport mechanism was confirmed by fitting data. Single-charge injection and the amorphous layer at the bonding interface are presumably the reasons to cause SCLCs.