Complexes of C and H in non-doped and Mg-doped epitaxial films were investigated by means of Fourier transform infra-red spectroscopy. Infra-red absorption peaks were observed at 2853, 2923 and 2956/cm in Mg-doped samples. The absorption peaks were attributed to the symmetrical and asymmetrical vibrational stretching modes of C-H in CHn defect complexes, where n ranged from 1 to 3. The C-H complexes were unintentionally incorporated during the growth of Mg-doped material. The absorbance of the vibrational modes increased in heavily Mg-doped samples. The complexes decomposed during annealing (700C, 0.5h) in a N environment.

G.C.Yi, B.W.Wessels: Applied Physics Letters, 1997, 70[3], 357-9