Berlin 2008 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 32: Quantum dots and wires: preparation and characterization I
HL 32.3: Talk
Wednesday, February 27, 2008, 14:45–15:00, ER 270
Optical and structural properties of transition metal implanted ZnO nanowires — •Sven Müller1, Carsten Ronning1, MinJie Zhou2, and Quan Li2 — 1II. Physikalisches Institut, Georg-August Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany — 2Department of Physics, Chinese University of Hong Kong, Shatin, New Territory, Hong Kong
Room temperature ferromagnetism has been proposed for Transitions metal (TM) doped ZnO, and therefore ZnO:TM is of high potential for spintronic applications [1]. Additionally, TM-doped semiconductors show optical active and sharp intra-3d-transition with long life-times. Such intra-shell transitions are usually forbidden, but due to the incorporation into a suitable matrix the crystal field splitting leads to long-life partly allowed transitions [2,3]. Fe, Ni or Co-ions were implanted into VLS-grown ZnO nanowires [4] with a box like profile and different fluences to obtain TM concentrations of 1, 2 and 4 at.%. The nanowires were annealed at 700°C for 30min in air. The morphology was examined by SEM and HR-TEM, revealing an intense damage of the nanowires surface and the crystal lattice. EDX and EELS measurements showed effective incorporation of the TM elements with the desired concentrations. The optical properties were investigated using PL/CL and show sharp intra-3d transitions of the corresponding TM.
[1] K. Sato et al., Phys. Status Solidi B 229, 673 (2002)
[2] H.A. Weakliem, J. Chem. Phys. 36, 2117 (1962)
[3] R. Heitz et al., Phys. Rev. B 45, 8977 (1992)
[4] C. Borchers et al., J. Phys. Chem. B 110, 1656 (2006)