141 citations · 757 across the 24 of their papers we have counts for
25 papers
Observation of dielectrically confined excitons in ultrathin GaN nanowires up to room temperature
Johannes K. Zettler, Pierre Corfdir, Christian Hauswald +10
The realization of semiconductor structures with stable excitons at room temperature is crucial for the development of excitonics and polaritonics. Quantum confinement has commonly…
A 3.5-THz, x6-Harmonic, Single-Ended Schottky Diode Mixer for Frequency Stabilization of Quantum-Cascade Lasers
Divya Jayasankar, Vladimir Drakinskiy, Nick Rothbart +8
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 dio…
Drastic effect of sequential deposition resulting from flux directionality on the luminescence efficiency of nanowire shells
Hanno Küpers, Ryan B. Lewis, Pierre Corfdir +6
Core-shell nanowire heterostructures form the basis for many innovative devices. When compound nanowire shells are grown by directional deposition techniques, the azimuthal positio…
Coherence Resonance and Stochastic Resonance in an Excitable Semiconductor Superlattice
Emanuel Mompo, Miguel Ruiz Garcia, Manuel Carretero +3
Collective electron transport causes a weakly coupled semiconductor superlattice under dc voltage bias to be an excitable system with degrees of freedom: electron densities…
Electronic and magnetic properties of -FeGe films embedded in vertical spin valve devices
Dietmar Czubak, Samuel Gaucher, Lars Oppermann +5
We studied metastable -FeGe, a novel layered tetragonal material, embedded as a spacer layer in spin valve structures with ferromagnetic FeSi and CoFeSi electrodes.…
Carrier diffusion in GaN -- a cathodoluminescence study. II: Ambipolar vs. exciton diffusion
Oliver Brandt, Vladimir M. Kaganer, Jonas Lähnemann +8
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 s…
Enhanced radiative efficiency in GaN nanowires grown on sputtered TiN: effects of surface electric fields
T. Auzelle, M. Azadmand, T. Flissikowski +8
GaN nanowires grown by molecular beam epitaxy generally suffer from dominant nonradiative recombination, which is believed to originate from point defects. To suppress the formatio…
Absence of quantum-confined Stark effect in GaN quantum disks embedded in (Al,Ga)N nanowires grown by molecular beam epitaxy
C. Sinito, P. Corfdir, C. Pfüller +14
Several of the key issues of planar (Al,Ga)N-based deep-ultraviolet light emitting diodes could potentially be overcome by utilizing nanowire heterostructures, exhibiting high stru…
Ga-polar (In,Ga)N/GaN quantum wells vs. N-polar (In,Ga)N quantum disks in GaN nanowires: Comparative analysis of carrier recombination, diffusion, and radiative efficiency
F. Feix, T. Flissikowski, K. K. Sabelfeld +5
We investigate the radiative and nonradiative recombination processes in planar (In,Ga)N/GaN(0001) quantum wells and (In,Ga)N quantum disks embedded in GaN nanowires…
Noise-enhanced chaos in a weakly coupled GaAs/(Al,Ga)As superlattice
Zhizhen Yin, Helun Song, Yaohui Zhang +5
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 simulat…
Nature of excitons bound to inversion domain boundaries: Origin of the 3.45-eV luminescence lines in spontaneously formed GaN nanowires on Si(111)
Carsten Pfüller, Pierre Corfdir, Christian Hauswald +9
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 pa…
Quenching of the luminescence intensity of GaN nanowires under electron beam exposure: Impact of C adsorption on the exciton lifetime
Jonas Lähnemann, Timur Flissikowski, Martin Wölz +4
Electron irradiation of GaN nanowires in a scanning electron microscope strongly reduces their luminous efficiency as shown by cathodoluminescence imaging and spectroscopy. We demo…
Individual electron and hole localization in submonolayer InN quantum sheets embedded in GaN
Felix Feix, Timur Flissikowski, Caroline Chèze +3
We investigate sub-monolayer InN quantum sheets embedded in GaN(0001) by temperature-dependent photoluminescence spectroscopy under both continuous-wave and pulsed excitation. Both…
Exciton dynamics in GaAs/(Al,Ga)As core-shell nanowires with shell quantum dots
Pierre Corfdir, Hanno Küpers, Ryan B. Lewis +4
We study the dynamics of excitons in GaAs/(Al,Ga)As core-shell nanowires by continuous-wave and time-resolved photoluminescence and photoluminescence excitation spectroscopy. Stron…
Crystal-phase quantum dots in GaN quantum wires
P. Corfdir, C. Hauswald, O. Marquardt +6
We study the nature of excitons bound to I1 basal plane stacking faults in ensembles of ultrathin GaN nanowires by continuous-wave and time-resolved photoluminescence spectroscopy.…
Radial Stark effect in (In,Ga)N nanowires
Jonas Lähnemann, Pierre Corfdir, Felix Feix +5
We study the luminescence of unintentionally doped and Si-doped InGaN nanowires with a low In content (x<0.2) grown by molecular beam epitaxy on Si substrates. The emis…
Stacking faults as quantum wells in nanowires: Density of states, oscillator strength and radiative efficiency
P. Corfdir, C. Hauswald, J. K. Zettler +6
We investigate the nature of excitons bound to I1 basal-plane stacking faults [(I1;X)] in GaN nanowire ensembles by continuous-wave and time-resolved photoluminescence spectroscopy…
Investigating the origin of the nonradiative decay of bound excitons in GaN nanowires
Christian Hauswald, Pierre Corfdir, Johannes K. Zettler +9
We investigate the origin of the fast recombination dynamics of bound and free excitons in GaN nanowire ensembles by temperature-dependent photoluminescence spectroscopy using both…
Luminescence associated with stacking faults in GaN
Jonas Lähnemann, Uwe Jahn, Oliver Brandt +3
Basal-plane stacking faults are an important class of optically active structural defects in wurtzite semiconductors. The local deviation from the 2H stacking of the wurtzite matri…
Coupling of exciton states as the origin of their biexponential decay dynamics in GaN nanowires
Christian Hauswald, Timur Flissikowski, Tobias Gotschke +4
Using time-resolved photoluminescence spectroscopy, we explore the transient behavior of bound and free excitons in GaN nanowire ensembles. We investigate samples with distinct dia…
Spatially resolved investigation of strain and composition variations in (In,Ga)N/GaN epilayers
Benjamin Wilsch, Uwe Jahn, Bernd Jenichen +2
The strain state and composition of a 400 nm thick (In,Ga)N layer grown by metal-organic chemical vapor deposition on a GaN template are investigated by spatially integrated x-ray…
Wave fronts, pulses and wave trains in photoexcited superlattices behaving as excitable or oscillatory media
J. I. Arana, L. L. Bonilla, H. T. Grahn
Undoped and strongly photoexcited semiconductor superlattices with field-dependent recombination behave as excitable or oscillatory media with spatially discrete nonlinear convecti…
Coexistence of quantum-confined Stark effect and localized states in an (In,Ga)N/GaN nanowire heterostructure
Jonas Lähnemann, Oliver Brandt, Carsten Pfüller +7
We analyze the emission of single GaN nanowires with (In,Ga)N insertions using both micro-photoluminescence and cathodoluminescence spectroscopy. The emission spectra are dominated…
Photo-excited semiconductor superlattices as constrained excitable media: Motion of dipole domains and current self-oscillations
J. I. Arana, L. L. Bonilla, H. T. Grahn
A model for charge transport in undoped, photo-excited semiconductor superlattices, which includes the dependence of the electron-hole recombination on the electric field and on th…