“…Nickel oxide (NiO) has been identified as a promising wide-bandgap p-type semiconductor complementary to the n-type Ga 2 O 3 . X. Lu and co-work-ers [8] summarize and discuss recent advances and challenges of NiO/Ga 2 O 3 heterojunction enabled power electronic devices. Recent progress regarding the construction and characterization methods as well as the device technology for NiO/Ga 2 O 3 heterojunctions are critically surveyed.…”