Complexes of H in epitaxial thin films were investigated by using Fourier transform infra-red spectroscopy. Undoped and Er-doped layers were grown by using low-pressure metal-organic chemical vapor deposition. The infra-red spectra of undoped and Er-doped films, which had been grown at 750 to 800C, revealed infra-red absorption at 3486/cm. This absorption peak was attributed to a vibrational mode of O-H. The Er-doped layers exhibited additional absorption peaks at 2905 and 2964/cm, and these were attributed to the vibrational modes of C-H complexes in Er-doped layers.

G.C.Yi, B.A.Block, B.W.Wessels: Applied Physics Letters, 1997, 71[3], 327-9