Due to their intrinsically large surface-to-volume ratio, nanowires and nanofins interact strongly with their environment. We investigate the role of the main air constituents nitrogen, oxygen and water on the efficiency of radiative recombination in GaN nanostructures as a function of different surface treatments and at temperatures up to 200 °C. Oxygen and water exposures exhibit a complex behavior as they can both act quenching and enhancing on the photoluminescence intensity dependent on the temperature.
View Article and Find Full Text PDFSurface-anisotropic nanoparticles represent a new class of materials that shows potential in a variety of applications, including self-assembly, microelectronics, and biology. Here, the first synthesis of surface-anisotropic silicon quantum dots (SiQDs), obtained through masking on 2D silicon nanosheets, is presented. SiQDs are deposited on the 2D substrate, thereby exposing only one side of the QDs, which is functionalized through well-established hydrosilylation procedures.
View Article and Find Full Text PDFResearch on optically resonant dielectric nanostructures has accelerated the development of photonic applications, driven by their ability to strongly confine light on the nanoscale. However, as dielectric resonators are typically operated below their band gap to minimize optical losses, the usage of dielectric nanoantenna concepts for absorption enhancement has largely remained unexplored. In this work, we realize engineered nanoantennas composed of photocatalytic dielectrics and demonstrate increased light-harvesting capabilities in otherwise weakly absorptive spectral regions.
View Article and Find Full Text PDFNanowire (NW) based devices for solar driven artificial photosynthesis have gained increasing interest in recent years due to the intrinsically high surface to volume ratio and the excellent achievable crystal qualities. However, catalytically active surfaces often suffer from insufficient stability under operational conditions. To gain a fundamental understanding of the underlying processes, the photochemical etching behavior of hexagonal and round GaN NWs in deionized water under illumination are investigated.
View Article and Find Full Text PDFParoxetine is a new compound in the group of the selective serotonin-reuptake inhibitors. The results of several open and double-blind control-group studies demonstrate clear antidepressive efficacy of paroxetine. However, most data were collected in samples of outpatients.
View Article and Find Full Text PDF