Growth of c-axis oriented gallium nitride thin films on an amorphous substrate by the liquid-target pulsed laser deposition technique

Gallium nitride (GaN) thin films with a wurtzite structure were grown on fused silica (FS) substrates by pulsed laser ablation of a liquid gallium target in the presence of ammonia gas. X-ray diffraction measurement shows a single c-axis orientation for the GaN film grown with a thin (<1000 Å) zinc oxide (ZnO) film as an alignment layer. There is a great improvement in the surface morphology as well as optical transmission for the GaN film grown on the ZnO buffered FS substrate. The energy band gap obtained from the absorption spectrum is about 3.45 eV.