Mechanism for low temperature activation of Mg-doped GaN with Ni catalysts

The activation mechanism of Mg-doped GaN with Ni catalysts has been investigated by thermal desorption spectroscopy. It has been revealed that Ni deposited on Mg-doped GaN enhances the hydrogen recombination reaction at temperatures below 200 °C with the activation energy of 1.3 eV. The hydrogen desorbed at this temperature can be attributed to a part of the passivating hydrogen in GaN with a weak binding energy. The enhancement of the hydrogen recombination reaction on the GaN surface is essential to decreasing hydrogen concentration efficiently at low temperatures.