We demonstrate that yellow luminescence often observed in both carbon-doped and pristine GaN is the result of electronic transitions via the ${\mathrm{C}}_{\mathrm{N}}\mathrm{\text{−}}{\mathrm{O}}_{\mathrm{N}}$ complex. In contrast to common isolated defects, the ${\mathrm{C}}_{\mathrm{N}}\mathrm{\text{−}}{\mathrm{O}}_{\mathrm{N}}$ complex is energetically favorable, and its calculated optical properties, such as absorption and emission energies, a zero phonon line, and the thermodynamic transition level, all show excellent agreement with measured luminescence data. Thus, by combining hybrid density functional theory and experimental measurements, we propose a solution to a long-standing problem of the GaN yellow luminescence.

• Received 11 September 2012

DOI:https://doi.org/10.1103/PhysRevLett.110.087404