Berlin 2015 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 34: Nitrides: Dots, rods, and structures
HL 34.2: Talk
Tuesday, March 17, 2015, 11:30–11:45, EW 201
Temperature dependence of the luminescence dynamics of InGaN/GaN MQW microrod structures — •Angelina Vogt1, Linus Krieg2, Matin Sadat Mohajerani1, Xue Wang1,3, Jana Hartmann1, Martin Straßburg3, Tilman Schimpke3, Hergo-Heinrich Wehmann1, Andreas Waag1, Jürgen Gutowski2, and Tobias Voss1 — 1Institute of Semiconductor Technology and LENA, TU Braunschweig — 2Institute of Solid State Physics, University of Bremen — 3Osram Opto Semiconductors GmbH
Three-dimensional core-shell GaN-based microrods with embedded InGaN multi-quantum-well structures (MQW) are promising candidates for sensors and light-emitting diodes in the green to ultraviolet spectral region. The large area of active layers in relation to the surface area of the substrate is one of the advantages of the microrod structures. Here, we study the temperature dependence of the luminescence dynamics of microrod LED structures with a picosecond time resolution. Their luminescence dynamics were studied in order to characterise the fundamental optical properties and to investigate the influence of varying sample compositions. We compare and discuss the luminescence dynamics of different InGaN/GaN microrod LEDs with regard to the variation of the decay time for different sample positions and temperatures. All samples show a characteristic decay time of the InGaN PL between 50 and 300 ps. In particular, the luminescence on the high energy side typically exhibits a faster decay than that on the low energy side. This is attributed to relaxation and recombination processes of the charge carriers in that energy range.