Heiko Bremers

Abstract: Using time-resolved photoluminescence spectroscopy on GaInN/GaN multiple quantum well structures, we analyze the radiative and nonradiative processes contributing to the “green gap” in GaN-based light emitting devices. We observe that it is only partly caused by a reduced oscillator strength due to the Quantum Confined Stark Effect (QCSE) which becomes stronger with increasing indium concentration and well width. As the dominant effect we observe a reduction of nonradiative lifetimes when the indium concentration is increased. For higher indium concentrations, we find an additional nonradiative recombination path that might be attributed to an increased generation of defects like misfit dislocations, nitrogen vacancies and/or indium clusters within the optically active region. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

TL;DR: In this paper, the origin of the green gap for GaInN/GaN quantum wells was investigated via temperature-dependent time-resolved photoluminescence spectroscopy.

TL;DR: In this paper, the dependence of the total recombination rate on excess carrier density was studied, up to rather high densities, and the authors found a room-temperature Auger recombination coefficient of 18.5 ± 1.2 × 10−31 cm6/s in the bandgap range 25 − 31 eV, considerably lower than previous experimental estimates.

TL;DR: In this article, the authors demonstrate quantitatively that the realization of high internal quantum efficiency of more than 70% at room temperature in quantum well structures is possible with potential barriers, which are caused by V-shaped pit formation around threading dislocations.

TL;DR: In this paper, the fabrication method and humidity sensing performances of zinc oxide nanorods (ZONRs) and chitosan self-assembled monolayers (SAMs) modified ZONRs patterned piezoresistive silicon MEMS microcantilevers were reported.