Role of hydrogen in doping of GaN

We investigate the interactions between hydrogen and dopant impurities in GaN, using state-of-the-art first-principles calculations. Our results for energetics and migration reveal a fundamental difference in the behavior of hydrogen between p-type and n-type material; in particular, we explain why hydrogen concentrations in n-type GaN are low, and why hydrogen has a beneficial effect on acceptor incorporation in p-type GaN. Our results identify the conditions under which hydrogen can be used to control doping in semiconductors in general.