Regensburg 2007 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 38: ZnO I

HL 38.11: Talk

Thursday, March 29, 2007, 12:45–13:00, H17

Cathodoluminescence study of ZnO layers grown on GaN — •Raoul Schneider, Martin Schirra, Anton Reiser, Günther Prinz, Rolf Sauer, and Klaus Thonke — Institut für Halbleiterphysik, Universität Ulm, D-89069 Ulm

Growth of ZnO layers on GaN substrates benefits from the small lattice mismatch of the two materials. We report on cathodoluminescence studies of ZnO layers grown by a modified CVD process on GaN templates deposited on sapphire substrates. The measurements were performed in a field-emitter type scanning electron microscope (FE-SEM) at low temperature and low acceleration voltages resulting in high spatial resolution below 80nm. A versatile detection system has been developed, which allows us to record single CL spectra, line scans and monochromatic CL images. Line scans across the GaN/ZnO interface reveal relaxation of strain and incorporation of Ga from the template into the ZnO layer. Monochromatic CL images of the edge and of the surface show a homogeneous distribution of the near band edge luminescence apart from single defects. First results of micro-Raman measurements are compared to the CL results.