Dresden 2006 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 26: II-VI semiconductors II

HL 26.7: Vortrag

Dienstag, 28. März 2006, 16:45–17:00, POT 51

Fe²⁺ in ZnO studied by Fourier-transform transmission spectroscopy — •Enno Malguth¹, Axel Hoffmann², Matthew Phillips¹, and B. Hausmann² — ¹Microstructural Analysis Unit, University of Technology, Sydney, Australia — ²Institut für Festkörperphysik, Technische Universität Berlin, Germany

ZnO crystals, coated with a 1 µm thick Fe layer and subsequently annealed under different atmospheres were studied by means of Fourier-transform infrared (FTIR) transmission spectroscopy. At 50 K, a pronounced absorption structure was detected around 395 meV exhibiting at least five distinct lines. Even at room temperature, a broad peak centered around 400 meV was observed. We attribute this absorption feature to the internal ⁵E—→⁵T₂ transition of the isolated Fe²⁺ center. This transition has been thoroughly studied in several cubic III-V and II-VI semiconductor materials, where it was found at similar energetic positions. However so far, it has not been established satisfactorily in ZnO where a crystal field of c_3V symmetry causes an additional splitting of the involved electronic states. By means of polarized measurements the observed lines are tentatively assigned to single transitions between ⁵E and ⁵T₂ sublevels according to transition rules.