291 citations · 1.8k across the 32 of their papers we have counts for
19 papers · 1 filter
Unravelling the oxygen influence in cubic bixbyite InO on Raman active phonon modes by isotope studies
Johannes Feldl, Roland Gillen, Janina Maultzsch +5
In this study, we performed comprehensive investigations on the Raman active phonon modes in cubic bixbyite InO, an important oxide based, wide-bandgap semiconductor. Funda…
Cove-edged Chiral Graphene Nanoribbons with Chirality-Dependent Bandgap and Carrier Mobility
K. Liu, W. Zheng, S. Osella +13
Graphene nanoribbons (GNRs) have garnered significant interest due to their highly customizable physicochemical properties and potential utility in nanoelectronics. Besides control…
Moiré lattice of twisted bilayer graphene as template for non-covalent functionalization
Tobias Dierke, Stefan Wolff, Roland Gillen +7
We present a novel approach to achieve spatial variations in the degree of non-covalent functionalization of twisted bilayer graphene (tBLG). The tBLG with twist angles varying bet…
Family behavior and Dirac bands in armchair nanoribbons with 4-8 defect lines
Roland Gillen, Janina Maultzsch
Bottom-up synthesis from molecular precursors is a powerful route for the creation of novel synthetic carbon-based low-dimensional materials, such as planar carbon lattices. The we…
Electronic Properties and Interlayer Interactions in Antimony Oxide Homo- and Heterobilayers
Stefan Wolff, Roland Gillen, Janina Maultzsch
Antimony shows promise as a two-dimensional (2D) mono-elemental crystal, referred to as antimonene. When exposed to ambient conditions, antimonene layers react with oxygen, forming…
First and Second Order Raman Spectroscopy of Monoclinic
Benjamin M. Janzen, Roland Gillen, Zbigniew Galazka +2
We employ a combined experimental-theoretical study of the first- and second-order Raman modes of monoclinic -GaO. The investigated materials is of particular intere…
Isotopic study of Raman active phonon modes in -GaO
Benjamin M. Janzen, Piero Mazzolini, Roland Gillen +5
Holding promising applications in power electronics, the wide band gap material gallium oxide has emerged as a vital alternative to materials like GaN and SiC. The detailed study o…
Two-Dimensional Antimony Oxide
Stefan Wolff, Roland Gillen, Mhamed Assebban +2
Two-dimensional (2D) antimony, so-called antimonene, can form antimonene oxide when exposed to air. We present different types of single- and few-layer antimony oxide structures, b…
Vibrational signatures of diamondoid dimers with large intramolecular London dispersion interactions
Christoph Tyborski, Tobias Hueckstaedt, Roland Gillen +5
We analyze the vibrational properties of diamondoid compounds via Raman spectroscopy. The compounds are interconnected with carbon-carbon single bonds that exhibit exceptionally la…
Phonon dispersion of MoS
Hans Tornatzky, Roland Gillen, Hiroshi Uchiyama +1
Transition metal dichalcogenides like MoS, MoSe, WS, and WSe have attracted enormous interest during recent years. They are van-der-Waals crystals with highly aniso…
Native point defects of semiconducting layered Bi2O2Se
Huanglong Li, Xintong Xu, Yi Zhang +3
Bi2O2Se is an emerging semiconducting, air-stable layered material (Nat. Nanotechnol. 2017, 12, 530; Nano Lett. 2017, 17, 3021), potentially exceeding MoS2 and phosphorene in elect…
Light-Matter Interactions in Two-Dimensional Transition Metal Dichalcogenides: Dominant Excitonic Transitions in mono- and few-layer MoX and Band Nesting
Roland Gillen, Janina Maultzsch
We report ab initio calculations of the dielectric function of six mono- and bilayer molybdenum dichalcogenides based in a Bethe Salpether equation+GW ansatz, focussing on…
Newly observed first-order resonant Raman modes in few-layer MoS
Nils Scheuschner, Roland Gillen, Matthias Staiger +1
We report two new first-order Raman modes in the spectra of few-layer MoS at 286~cm and 471~cm for excitation energies above 2.4~eV. These modes appear only in fe…
Beyond double-resonant Raman scattering: UV Raman spectroscopy on graphene, graphite and carbon nanotubes
Christoph Tyborski, Felix Herziger, Roland Gillen +1
We present an analysis of deep-UV Raman measurements of graphite, graphene and carbon nanotubes. For excitation energies above the strong optical absorption peak at the point i…
Photoluminescence of freestanding single- and few-layer MoS2
Nils Scheuschner, Oliver Ochedowski, Anne-Marie Kaulitz +3
We present a photoluminescence study of freestanding and Si/SiO2 supported single- and few-layer MoS2. The single-layer exciton peak (A) is only observed in freestanding MoS2. The…
Accurate screened exchange band structures for transition metal monoxides MnO, FeO, CoO and NiO
Roland Gillen, John Robertson
We report calculations of the band structures and density of states of the four transition metal monoxides MnO, FeO, CoO and NiO using the hybrid density functional sX-LDA. Late tr…
The nature of the electronic band gap in lanthanide oxides
Roland Gillen, Stewart J. Clark, John Robertson
Accurate electronic structures of the technologically important lanthanide/rare earth sesquioxides (Ln2O3, with Ln=La,...,Lu) and CeO2 have been calculated using hybrid density fun…
Hybrid functional calculations of the Al impurity in silica: Hole localization and electron paramagnetic resonance parameters
Roland Gillen, John Robertson
We performed first-principle calculations based on the supercell and cluster approaches to investigate the neutral Al impurity in smoky quartz. Electron paramagnetic resonance meas…
Vibrational properties of graphene nanoribbons by first-principles calculations
Roland Gillen, Marcel Mohr, Janina Maultzsch +1
We investigated the vibrational properties of graphene nanoribbons by means of first-principles calculations on the basis of density functional theory. We confirm that the phonon m…