Optical and theoretical investigations of V2+ ion in GaN

The infrared luminescence of vanadium‐doped gallium nitride (GaN:V) grown by metalorganic vapour phase epitaxy technique (MOVPE) on SiN‐treated sapphire substrate were examined. Two spin allowed transitions were observed at 6633 cm‐1 and 6959 cm‐1, and are respectively assigned to the 4T1(4P)→4T1(4F) and 4A2(4F) → 4T1(4F) transition of V2+ (3d3) in a tetrahedral symmetry with a 4T1 ground state. Crystal‐field calculation of the detected transition energies based on the Tanabe‐Sugano scheme is presented. Good agreements between theoretical and experimental energy levels are obtained. The presence of a series of vibronic state is also discussed in this work (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)