相关论文: Enhanced radiative efficiency in GaN nanowires gro…
Trap-assisted nonradiative recombination has been shown to limit the efficiency of optoelectronic devices. While substitutional carbon ($\mathrm{C_N}$) has been suggested to be a nonradiative recombination center in GaN devices, a complete…
GaN/AlN nanowire heterostructures can display photoluminescence (PL) decay times on the order of microseconds that persist up to room temperature. Doping the GaN nanodisk insertions with Ge can reduce these PL decay times by two orders of…
The effect of film morphology on its surface chemistry and band structure has been analyzed for gallium nitride epitaxial films grown by molecular beam epitaxy. The film morphology has been studied using scanning electron microscopy and…
We investigate the electrical properties of nominally undoped, 10-40-nm-thick ScN(111) layers grown on nearly lattice-matched GaN:Fe/Al$_2$O$_3$(0001) templates by plasma-assisted molecular beam epitaxy. Hall-effect measurements yield…
Quantum confinement profoundly affects the properties and interactions of electrons, holes, and excitons in nanomaterials. We apply first-principles calculations to study the effects of extreme quantum confinement on the electronic,…
Using time-resolved photoluminescence spectroscopy, we explore the transient behavior of bound and free excitons in GaN nanowire ensembles. We investigate samples with distinct diameter distributions and show that the pronounced…
Mn concentration depth profiles in Mn-doped GaAs thin films grown at substrate temperatures of 580 and 250 {\deg}C using various Mn cell temperatures have been investigated with dynamic secondary ion mass spectrometry and Auger electron…
We present a set of experimental results identifying various effects that govern the carrier dynamics of self-catalyzed GaAs/AlGaAs core-shell nanowires (NWs) grown by molecular beam epitaxy i.e. surface recombination velocity, surface…
V-pit-defects in GaN-based light-emitting diodes induced by dislocations are considered beneficial to electroluminescence because they relax the strain in InGaN quantum wells and also enhance the hole lateral injection through sidewall of…
Transition-metal nitrides constitute a versatile class of materials with diverse properties and wide-ranging applications. Exploring new surface orientations and uncovering novel properties can enable innovative material configurations with…
Indium incorporation and surface morphology of InAlN layers grown on (0001)GaN by plasma-assisted molecular beam epitaxy were investigated as a function of the impinging In flux and the substrate temperature in the 450-610$^{\circ}$C range.…
Heteroepitaxy conventionally relies on rigid crystalline substrates, implicitly assuming that lattice and thermal mismatch must be accommodated within the epitaxial layer, leading to residual strain and defects that worsen with increasing…
The addition of boron to GaAs nanowires grown by self-catalyzed molecular beam epitaxy was found to have a strong effect on the nanowire morphology, with axial growth greatly reduced as the nominal boron concentration was increased.…
By employing a mixed SnO$_2$+Sn source, we demonstrate suboxide molecular beam epitaxy growth of phase-pure single crystalline metastable SnO(001) thin films at a growth rate of ~1.0nm/min without the need for additional oxygen. These films…
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 zero to about 20%. Within the nanowire ensemble, the MQWs…
III-V nanowire heterostructures can act as sources of single and entangled photons and are enabling technologies for on-chip applications in future quantum photonic devices. The unique geometry of nanowires allows to integrate…
We report on the exciton propagation in polar (Al,Ga)N/GaN quantum wells over several micrometers and up to room temperature. The key ingredient to achieve this result is the crystalline quality of GaN quantum wells (QWs) grown on GaN…
Gallium arsenide nanowires were synthesized by gallium-assisted molecular beam epitaxy. By varying the growth time, nanowires with diameters ranging from 30 to 160 nm were obtained. Raman spectra of the nanowires ensembles were measured.…
GaAs/Fe$_{3}$Si core/shell nanowire structures were fabricated by molecular-beam epitaxy on oxidized Si(111) substrates and investigated by synchrotron x-ray diffraction. The surfaces of the Fe$_3$Si shells exhibit nanofacets. These facets…
SnTe topological crystalline insulator nanowires have been grown by molecular beam epitaxy on graphene/SiC substrates. The nanowires have cubic rock-salt structure, they grow along [001] crystallographic direction and have four sidewalls…