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HL: Fachverband Halbleiterphysik
HL 27: II-VI semiconductors
HL 27.9: Talk
Wednesday, March 28, 2007, 16:30–16:45, H13
Near bandgap photoluminescence spectroscopy of ZnO nanowires embedded in PMMA — •Jan-Peter Richters, Lars Wischmeier, Ilja Rückmann, and Jürgen Gutowski — Institute of solid state physics, University of Bremen, P.O. Box 330440, D-28334 Bremen
Due to their large surface-to-volume ratio and the photon confinement, ZnO nanowires are expected to be good candidates for applications in nanoscaled optoelectronics in the blue spectral region and for sensor applications. For some reasons it is useful to embed the ZnO nanowires into a surrounding matrix to influence the surface or interface states and the waveguiding properties. Here, we report about studies of the low-temperature photoluminescence (PL) of ZnO nanowires embedded in the polymer PMMA. For this we used VLS grown ZnO nanowire ensembles to prepare insular wire samples. Wires were stripped from the ensemble, dissolved in PMMA and acetone, and finally spin-coated on aluminium substrates. For measurements on single wires we used a micro-PL setup. PL spectra of the nanowire ensemble, of single wires without matrix and single wires embedded in PMMA were studied and compared. In general the near-band-edge spectra are dominated by D0X bound-exciton lines, by an asymmetric surface exciton band (SX), and by phonon replicas. Due to the PMMA matrix the intensity ratios of the above mentioned lines are strongly changed. Additionally the green defect luminescence is suppressed.