Thermal conductivity of lateral epitaxial overgrown GaN films

The room-temperature thermal conductivity of lateral epitaxial overgrown metalorganic chemical vapor deposition GaN films is reported to be in excess of 155 W/m K. This compares with the reported value of 130 W/m K for bulk single crystals and a similar value (135 W/m K) for a thick (∼50 μm) GaN film grown, without a nucleation layer, on sapphire by hydride vapor phase epitaxy. The measurements were made by a third-harmonic electrical measurement.