Free Catalyst Synthesis of GaN Nanostructures on Si-Substrate via CVD

Abstract

In this article gallium nitride (GaN) nanostructures have been grown through chemical vapor deposition (CVD) on Silicon substrate, no metal catalyst was used. A high purity of gallium nitride powder was evaporated at 1150°C for 3 hour and then annealed at temperature 1000°C under flow of ammonia (NH3)gas. XRD shows the diffraction peaks located at 2θ= 32.4, 34.4, 36.8, 48.1, 57.8, 63.5, 68.3, 69.2° corresponding to the (100), (002), (101), (102), (110), (103), (200) and (112) diffraction planes of the product. These results revealed that the diffraction peaks can be attributed to the hexagonal GaN phase with lattice constant of a = 3.189 Å and c = 5.200 Å. Raman scattering spectrum shows four phonons mode correspond to GaN nanostructure are detected at 560, 570, 720 and 740 cm-1corresponding E1(TO), E2(high),A1(LO) and E1(LO) respectively. Photoluminescence (PL) of the GaN nanostructure exhibited two emission peaks, a weak and broad ultraviolet (UV) light emission peak at 390 nm and a strong yellow light (YL) emission peak at 550 nm.