Zobrazeno 1 - 10
of 217
pro vyhledávání: '"Grahn, Holger T."'
Autor:
Zettler, Johannes K., Corfdir, Pierre, Hauswald, Christian, Luna, Esperanza, Jahn, Uwe, Flissikowski, Timur, Schmidt, Emanuel, Ronning, Carsten, Trampert, Achim, Geelhaar, Lutz, Grahn, Holger T., Brandt, Oliver, Fernández-Garrido, Sergio
Publikováno v:
Nano Letters 2016, 16, 2, 973
The realization of semiconductor structures with stable excitons at room temperature is crucial for the development of excitonics and polaritonics. Quantum confinement has commonly been employed for enhancing excitonic effects in semiconductor hetero
Externí odkaz:
http://arxiv.org/abs/2401.16868
Autor:
Küpers, Hanno, Lewis, Ryan B., Corfdir, Pierre, Niehle, Michael, Flissikowski, Timur, Grahn, Holger T., Trampert, Achim, Brandt, Oliver, Geelhaar, Lutz
Core-shell nanowire heterostructures form the basis for many innovative devices. When compound nanowire shells are grown by directional deposition techniques, the azimuthal position of the sources for the different constituents in the growth reactor,
Externí odkaz:
http://arxiv.org/abs/2106.12309
Autor:
Jayasankar, Divya, Drakinskiy, Vladimir, Rothbart, Nick, Richter, Heiko, Lü, Xiang, Schrottke, Lutz, Grahn, Holger T., Wienold, Martin, Hübers, Heinz-Wilhelm, Sobis, Peter, Stake, Jan
Efficient and compact frequency converters are essential for frequency stabilization of terahertz sources. In this paper, we present a 3.5-THz, x6-harmonic, integrated Schottky diode mixer operating at room temperature. The designed frequency convert
Externí odkaz:
http://arxiv.org/abs/2107.03532
Autor:
Mompo, Emanuel, Garcia, Miguel Ruiz, Carretero, Manuel, Grahn, Holger T., Zhang, Yaohui, Bonilla, Luis L.
Publikováno v:
Physical Review Letters 121, 086805 (2018)
Collective electron transport causes a weakly coupled semiconductor superlattice under dc voltage bias to be an excitable system with $2N+2$ degrees of freedom: electron densities and fields at $N$ superlattice periods plus the total current and the
Externí odkaz:
http://arxiv.org/abs/2011.09327
Autor:
Czubak, Dietmar, Gaucher, Samuel, Oppermann, Lars, Herfort, Jens, Zollner, Klaus, Fabian, Jaroslav, Grahn, Holger T., Ramsteiner, Manfred
We studied metastable $\alpha$-FeGe$_2$, a novel layered tetragonal material, embedded as a spacer layer in spin valve structures with ferromagnetic Fe$_3$Si and Co$_2$FeSi electrodes. For both types of electrodes, spin valve operation is demonstrate
Externí odkaz:
http://arxiv.org/abs/2010.04453
Autor:
Brandt, Oliver, Kaganer, Vladimir M., Lähnemann, Jonas, Flissikowski, Timur, Pfüller, Carsten, Sabelfeld, Karl K., Kireeva, Anastasya E., Chèze, Caroline, Calarco, Raffaella, Grahn, Holger T., Jahn, Uwe
Publikováno v:
Phys. Rev. Applied 17, 024018 (2022)
We determine the diffusion length of excess carriers in GaN by spatially resolved cathodoluminescence spectroscopy utilizing a single quantum well as carrier collector or carrier sink. Monochromatic intensity profiles across the quantum well are reco
Externí odkaz:
http://arxiv.org/abs/2009.13983
Autor:
Yin, Zhizhen, Song, Helun, Zhang, Yaohui, Ruiz-Garcia, Miguel, Carretero, Manuel, Bonilla, Luis L., Biermann, Klaus, Grahn, Holger T.
Noise-enhanced chaos in a doped, weakly coupled GaAs/Al_{0.45}Ga_{0.55}As superlattice has been observed at room temperature in experiments as well as in the results of the simulation of nonlinear transport based on a discrete tunneling model. When e
Externí odkaz:
http://arxiv.org/abs/1701.02510
Autor:
Pfüller, Carsten, Corfdir, Pierre, Hauswald, Christian, Flissikowski, Timur, Kong, Xiang, Zettler, Johannes K., Fernández-Garrido, Sergio, Doğan, Pınar, Grahn, Holger T., Trampert, Achim, Geelhaar, Lutz, Brandt, Oliver
Publikováno v:
Phys. Rev. B 94, 155308 (2016)
We investigate the 3.45-eV luminescence band of spontaneously formed GaN nanowires on Si(111) by photoluminescence and cathodoluminescence spectroscopy. This band is found to be particularly prominent for samples synthesized at comparatively low temp
Externí odkaz:
http://arxiv.org/abs/1607.04036
Autor:
Lähnemann, Jonas, Flissikowski, Timur, Wölz, Martin, Geelhaar, Lutz, Grahn, Holger T., Brandt, Oliver, Jahn, Uwe
Publikováno v:
Nanotechnology 27, 455706 (2016)
Electron irradiation of GaN nanowires in a scanning electron microscope strongly reduces their luminous efficiency as shown by cathodoluminescence imaging and spectroscopy. We demonstrate that this luminescence quenching originates from a combination
Externí odkaz:
http://arxiv.org/abs/1607.03397
Autor:
Feix, Felix, Flissikowski, Timur, Chèze, Caroline, Calarco, Raffaella, Grahn, Holger T., Brandt, Oliver
Publikováno v:
Appl. Phys. Lett. 109, 042104 (2016)
We investigate sub-monolayer InN quantum sheets embedded in GaN(0001) by temperature-dependent photoluminescence spectroscopy under both continuous-wave and pulsed excitation. Both the peak energy and the linewidth of the emission band associated wit
Externí odkaz:
http://arxiv.org/abs/1605.00865