Berlin 2008 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 32: Quantum dots and wires: preparation and characterization I

HL 32.3: Vortrag

Mittwoch, 27. Februar 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)