Improvements of the optical and electrical properties of GaN films by using in-doping method during growth

The optical and electrical properties of GaN films grown by using In-doping method during growth have been investigated. The GaN films were grown on alpha-Al2O3(0001) substrates by gas-source molecular beam epitaxy. X-ray diffraction measurements illustrate that the quality of GaN films were improved by In-doping. Photoluminescence measurements at 10 K show that the band-edge related emission of GaN was enhanced by more than one order of magnitude by this In-doping method, while the luminescence originating from D-A pair recombination and structural defects, or possibly oxygen, was reduced. Furthermore, Hall effect measurements at room temperature (300 K) gave a higher Hall mobility of In-doped samples than non-doped one. The technique of In-doping during GaN growth looks promising for improving the optical and electrical properties of optic and electronic devices.