Dresden 2011 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 16: Microcavities

HL 16.7: Talk

Monday, March 14, 2011, 16:15–16:30, FOE Anorg

Optical properties of monolithic InGaN quantum dot pillar microcavities — •Kathrin Sebald, Moritz Seyfried, Joachim Kalden, Heiko Dartsch, Christian Tessarek, Stephan Figge, Carsten Kruse, Detlef Hommel, and Jürgen Gutowski — Institute of Solid State Physics, University of Bremen, Germany

The realization of monolithic microcavities (MCs) with InGaN quantum dots (QDs) as active region can improve the performance of VCSELs as well as the single-mode emission of pillar structured MCs. In this contribution, we will present the successful implementation of InGaN QDs into fully epitaxial monolithic MCs showing discrete resonator modes for pillar structured samples and emission lines of single QDs. The complete structure, consisting of two DBRs surrounding the GaN λ cavity, was grown by MOVPE. A layer of InGaN QDs was embedded in the cavity at the antinode position of the electric field. Pillar shaped MCs with various diameters were prepared from the planar samples by FIB etching. Their three-dimensional optical confinement results in the clear occurrence of a transversal mode structure. Quality factors of up to 300 have been achieved. Furthermore, micro-photoluminescence spectra reveal distinct spectrally sharp emission lines around 2.73eV which can be attributed to the emission of single InGaN QDs. Their markedly enhanced intensities when compared to QD lines off resonance give clear evidence of these QDs to efficiently couple to the modes. Single emission lines can be traced up to 120K. These finding are very encouraging, and further optimization gives the opportunity for an efficient utilization of InGaN QD-based devices.