122 citations · 711 across the 26 of their papers we have counts for
26 papers
ScN/GaN(): a new platform for the epitaxy of twin-free metal-semiconductor heterostructures
Philipp John, Achim Trampert, Duc Van Dinh +6
We study the molecular beam epitaxy of rock-salt ScN on the wurtzite GaN() surface. To this end, ScN is grown on free-standing GaN() substrates and self-ass…
Optical properties of ScN layers grown on AlO(0001) by plasma-assisted molecular beam epitaxy
Duc V. Dinh, Frank Peiris, Jonas Lähnemann +1
An accurate knowledge of the optical constants (refractive index and extinction coefficient ) of ScN is crucial for understanding the optical properties of this binary nitri…
Growth kinetics and substrate stability during high-temperature molecular beam epitaxy of AlN nanowires
Philipp John, Mikel Gómez Ruiz, Len van Deurzen +5
We study the molecular beam epitaxy of AlN nanowires between 950 and 1215 °C, well above the usual growth temperatures, to identify optimal growth conditions. The nanowires are gro…
Lattice parameters of ScAlN layers grown on GaN(0001) by plasma-assisted molecular beam epitaxy
Duc V. Dinh, Jonas Lähnemann, Lutz Geelhaar +1
An accurate knowledge of the lattice parameters of the new nitride ScAlN is essential for understanding the elastic and piezoelectric properties of this…
Molecular beam epitaxy of single-crystalline bixbyite (InGa)O films (): Structural properties and consequences of compositional inhomogeneity
Alexandra Papadogianni, Charlotte Wouters, Robert Schewski +9
In this work, we show the heteroepitaxial growth of single-crystalline bixbyite (InGa)O films on (111)-oriented yttria-stabilized zirconia substrates using plas…
Bandgap widening and behavior of Raman-active phonon modes of cubic single-crystalline (In,Ga)O alloy films
Johannes Feldl, Martin Feneberg, Alexandra Papadogianni +5
The influence of Ga incorporation into cubic InO on the electronic and vibrational properties is discussed for (In,Ga)O alloy films grown by molecular b…
Carrier diffusion in GaN -- a cathodoluminescence study. III: Nature of nonradiative recombination at threading dislocations
Jonas Lähnemann, Vladimir M. Kaganer, Karl K. Sabelfeld +5
We investigate the impact of threading dislocations with an edge component (a or a+c-type) on carrier recombination and diffusion in GaN(0001) layers close to the surface as well a…
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…
Carrier diffusion in GaN -- a cathodoluminescence study. I: Temperature-dependent generation volume
Uwe Jahn, Vladimir M. Kaganer, Karl K. Sabelfeld +8
The determination of the carrier diffusion length of semiconductors such as GaN and GaAs by cathodoluminescence imaging requires accurate knowledge about the spatial distribution o…
Self-assembly of well-separated AlN nanowires directly on sputtered metallic TiN films
Mani Azadmand, Tomas Auzelle, Jonas Lähnemann +7
We demonstrate the self-assembled formation of AlN nanowires by molecular beam epitaxy on sputtered TiN films on sapphire. This choice of substrate allows growth at an exceptionall…
Electroluminescence and current-voltage measurements of single (In,Ga)N/GaN nanowire light-emitting diodes in the nanowire ensemble
David van Treeck, Johannes Ledig, Gregor Scholz +7
We present the combined analysis of the electroluminescence (EL) as well as the current-voltage (I-V) behavior of single, freestanding (In,Ga)N/GaN nanowire (NW) light-emitting dio…
Effect of the nanowire diameter on the linearity of the response of GaN-based heterostructured nanowire photodetectors
Maria Spies, Jakub Polaczyński, Akhil Ajay +5
Nanowire photodetectors are investigated because of their compatibility with flexible electronics, or for the implementation of on-chip optical interconnects. Such devices are char…
Correlated nanoscale analysis of the emission from wurtzite versus zincblende (In,Ga)As/GaAs nanowire core-shell quantum wells
Jonas Lähnemann, Megan O. Hill, Jesús Herranz +12
While the properties of wurtzite GaAs have been extensively studied during the past decade, little is known about the influence of the crystal polytype on ternary (In,Ga)As quantum…
Near- and mid-infrared intersubband absorption in top-down GaN/AlN nano- and micropillars
Jonas Lähnemann, David A. Browne, Akhil Ajay +5
We present a systematic study of top-down processed GaN/AlN heterostructures for intersubband optoelectronic applications. Samples containing quantum well superlattices that displa…
Bias-controlled spectral response in GaN/AlN single-nanowire ultraviolet photodetectors
Maria Spies, Martien I. Den Hertog, Pascal Hille +6
We present a study of GaN single-nanowire ultraviolet photodetectors with an embedded GaN/AlN superlattice. The heterostructure dimensions and doping profile were designed in such…
Luminescent N-polar (In,Ga)N/GaN quantum wells grown by plasma-assisted molecular beam epitaxy at high temperature
C. Chèze, F. Feix, J. Lähnemann +6
N-polar (In,Ga)N/GaN quantum wells prepared on freestanding GaN substrates by plasma-assisted molecular beam epitaxy at conventional growth temperatures of about 650 °C do not exhi…
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…
Hydride Vapor Phase Epitaxy of GaN on Silicon Covered by Nanostructures
U. Jahn, M. Musolino, J. Lähnemann +8
Several ten m GaN have been deposited on a silicon substrate using a two-step hydride vapor phase epitaxy (HVPE) process. The substrates have been covered by AlN layers and GaN…
Comparison of the luminous efficiency of Ga- and N-polar InGaN/InGaN quantum wells grown by plasma-assisted molecular beam epitaxy
Sergio Fernández-Garrido, Jonas Lähnemann, Christian Hauswald +5
We investigate the luminescence of Ga- and N-polar InGaN/InGaN quantum wells (QWs) grown by plasma-assisted molecular beam epitaxy on freestanding GaN a…
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…
Localization and defects in axial (In,Ga)N/GaN nanowire heterostructures investigated by spatially-resolved luminescence spectroscopy
Jonas Lähnemann, Christian Hauswald, Martin Wölz +4
(In,Ga)N insertions embedded in self-assembled GaN nanowires are of current interest for applications in solid state light emitters. Such structures exhibit a notoriously broad emi…
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…
Correlation between In content and emission wavelength of InGaN/GaN nanowire heterostructures
Martin Wölz, Jonas Lähnemann, Oliver Brandt +7
GaN nanowire ensembles with axial InGaN multi-quantum wells (MQWs) were grown by molecular beam epitaxy. In a series of samples, we varied the In content in the MQWs from almost ze…
Direct experimental determination of the spontaneous polarization of GaN
Jonas Lähnemann, Oliver Brandt, Uwe Jahn +8
We present a universal approach for determining the spontaneous polarization Psp of a wurtzite semiconductor from the emission energies of excitons bound to the different types of…