Site-selective X-ray absorption fine-structure analysis, using X-ray-excited optical luminescence was performed in order to determine the local structure of an optically active center in Er-doped thin films. The X-ray absorption fine-structure spectrum at the Er LIII edge was obtained from the X-ray photon energy dependence of the peak intensity of infra-red luminescence due to Er intra-4f transitions. This method provided structural information only for optically active Er. A broad 1p-5d resonant peak in the site-selective X-ray absorption fine-structure spectrum was reproduced by means of a density-of-states calculation of a distorted ErO6 cluster; assuming Er transformation from an octahedral center of 0.025nm.

Site-Selective X-Ray Absorption Fine Structure Analysis of an Optically Active Centre in Er-Doped Semiconductor Thin Film Using X-Ray-Excited Optical Luminescence. M.Ishii, Y.Tanaka, T.Ishikawa, S.Komuro, T.Morikawa, Y.Aoyagi: Applied Physics Letters, 2001, 78[2], 183-5