Growth of network structured carbon-doped GaN (GaN:C) nanowires using a modified metal-organic chemical vapor deposition

• Network structural GaN:C nanowires (NWs) were formed without catalyst by MOCVD.
• Non-stoichiometric concentration of TMGa and HCl led to the formation of GaN:C NWs.
• The key process was the formation of polymerized GaClx containing methyl groups.

A network structured carbon-doped GaN (GaN:C) nanowires (NWs) was formed by a modified metal-organic chemical vapor deposition (MOCVD) technique using Ga(CH3)3, HCl and NH3 as precursors. The GaN:C NWs were acquired from a non-stoichiometric ratio of Ga(CH3)3 and HCl, and the key process is believed to be the formation of polymerized GaClx containing methyl groups. As-formed GaN:C NWs exhibited a hexagonal Wurtzite structure. The Ga to N elemental ratio was approximately 1:1, and the GaN:C NWs contained carbon with concentration of ∼5%. The GaN:C NWs showed the blue luminescence (BL) at 2.69 eV, which was conjectured to originate from the CN+–CN0 transitions. The method developed in this study could produce a network structure of GaN:C NWs without using catalysts. Moreover, carbon doping was found to be one of the candidates to change the optoelectronic properties of GaN.