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HL: Fachverband Halbleiterphysik

HL 37: ZnO: devices

HL 37.1: Vortrag

Mittwoch, 25. März 2009, 16:15–16:30, POT 51

Optical characterization of zinc oxide microwire lasers — •Christian Czekalla, Chris Sturm, Rüdiger Schmidt-Grund, Jesus Zuniga Perez, Michael Lorenz, and Marius Grundmann — Universität Leipzig, Fakultät für Physik und Geowissenschaften, Institut für Experimentelle Physik II, Linnéstr. 5, 04103, Leipzig, Germany

We report the optical characterization including photoluminescence (PL) spectroscopy and optical pumping of hexagonally shaped zinc oxide (ZnO) microwires. The structures were grown by a simple carbothermal evaporation process. Under high excitation conditions, whispering gallery mode lasing can be observed [1]. The observed lasing peaks can be calculated very precisely from a simple plane wave model [2]. The lasing modes exhibit a full width at half maximum (FWHM) of down to 0.6 meV, limited solely by radiation loss in good agreement with the theory of hexagonal cavities [3]. This leads to quality factors of about 4000.

In order to tune the emitted photon energy of the microwire lasers, MgZnO/ZnO core shell heterostructures have been grown around the microwires by pulsed laser deposition. The PL results clearly indicate the growth of MgZnO barriers and ZnO quantum wells. Additionally, high excitation spectroscopy results will be shown.

[1] C. Czekalla et al., Appl. Phys. Lett. 92, 241102 (2008)

[2] T. Nobis et al., Phys. Rev. Lett. 93, 103903 (2004)

[3] J. Wiersig, Phys. Rev. A 67, 023807 (2003)