Improved optical and electrical properties of low-temperature sputtered GaN by hydrogenation

The room-temperature photoluminescence intensity and conductivity of GaN films grown by reactive rf sputtering were improved by the addition of hydrogen during growth. The differential resistivity decreased by two orders of magnitude when 2.4% H 2 was added to the deposition gas. The improvement in the photoluminescence intensity occurred together with an increase in the level of oxygen contamination and an apparent increase in the structural disorder. At 0 and 20% H 2 , respectively, the refractive indices were 2.45 and 1.98, and the bandgaps were 3.06 and 3.64 eV , with the change attributed to oxygenation.