LAUSR

Abstract The Fano resonance photoemission study of the Pb0.97Ge0.03Te crystal doped by sequential deposition of Sm atoms on the clean [111] surface was performed to determine the contribution of the Sm4f electrons to the valence band of the Pb0.97Ge0.03Te/Sm crystal and to monitor the process of introduction of Sm into the substrate crystal host lattice. After each deposition step and after subsequent thermal treatment the contribution of both Sm2+ and Sm3+ ions were assessed. The analysis of the acquired data and a comparison with the results of similar studies of Sm doped CdTe, ZnO and GaN show that the thermal treatment at 250 °C of the Sm/Pb0.97Ge0.03Te system leads to conversion of Sm2+ to Sm3+ and probably to Sm4+ which corresponds to the valence of the cations in the substrate crystal host lattice.