The excitation spectra of trigonal and orthorhombic Fe-In pairs were studied by means of Fourier transform spectroscopy. The spectral features were attributed to hole transitions from the deep ground state to shallow hole states. It was found that the orthorhombic configuration was stable, but that the population of the metastable trigonal configuration was obtained by above-bandgap excitation. In the case of the orthorhombic and trigonal centers, the positions of the 0/- Fe-In levels were estimated to be 0.390 and 0.320eV below the conduction band minima. It was suggested that, in the trigonal center, Fe resided at the nearest-neighbor interstitial position.

P.Tidlund, M.Kleverman, H.G.Grimmeiss: Semiconductor Science and Technology, 1996, 11[5], 748-52