Theory of hot-carrier-induced phenomena in GaN high-electron-mobility transistors

It has long been known that GaN high-electron-mobility transistors can degrade significantly under hot electron stress. More recently, an increase in the yellow luminescence was observed under similar stress conditions. The two phenomena have been attributed to defects but no specific physical mechanism has been proposed. Here we report first-principles density-functional calculations of hydrogenated Ga vacancies and show that hydrogen release by hot electrons provides an explanation for both phenomena.