Nils Wilhelm Rosemann

Nils Wilhelm Rosemann
Karlsruhe Institute of Technology | KIT · Institute of Microstructure Technology

Dr. rer. nat.

About

41
Publications
4,247
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
533
Citations
Additional affiliations
June 2020 - present
Karlsruhe Institute of Technology
Position
  • PostDoc Position
Description
  • With a Return Fellowship of the Alexander von Humboldt Foundation I came back to germany to buildup my own research group and concentrate on topics like: Device integration of ultra-low threshold nonlinear reponse of amorphous organotin-sulfide cluster-compounds.
October 2019 - June 2020
Lund University
Position
  • PostDoc Position
Description
  • After my Feodor Lynen Research Fellowship I extended my stay at Lund University as a PostDoc in the department of chemical physics. With the research topic still concentrating on: ultra-fast spectroscopy on novel iron carbene based dye molecules.
October 2017 - October 2019
Lund University
Position
  • PostDoc Position
Description
  • With a Feodor Lynen Research Fellowship of the Alexander von Humboldt Foundation I was associated to the centre for analysis and synthesis and mainly working at the department of chemical physics. My research topic was ultra-fast spectroscopy on novel iron carbene based dye molecules.
Education
September 2012 - July 2016
Philipps University of Marburg
Field of study
  • Physics
October 2006 - December 2011
Philipps University of Marburg
Field of study
  • Physics

Publications

Publications (41)
Article
The Front Cover illustrates the generation of a transmission electron microscopy diffraction pattern from an amorphous adamantane‐type cluster compound and the conversion of infrared laser light into directed white light. Cover design by Elisa Monte. More information can be found in the Research Article by Kerstin Volz and co‐workers.
Article
The front cover artwork is provided by Johannes Haust, Jürgen Belz, Kerstin Volz (Philipps‐University Marburg) and Sangam Chatterjee (Justus Liebig University Giessen). The image illustrates the generation of a transmission electron microscopy diffraction pattern from the amorphous adamantane‐type cluster compound [(PhSn)4S6] (Ph=phenyl) as well as...
Article
The development of efficient and high‐brilliance white‐light sources is an essential contribution to innovative emission technologies. Materials exhibiting strong non‐linear optical properties, in particular second harmonic generation (SHG) or white‐light generation (WLG), have therefore been investigated with great activity in recent times. While...
Preprint
Full-text available
The most commonly used nonlinear optical process is the conversion of infrared light at 1064nm to green light at 532nm, as performed in common laser pointers. However, more relevant for future applications are nonlinear optical processes that generate a broad spectrum, a so called supercontinuum. A desirable goal is generating a spectrum that cover...
Preprint
Amorphous materials are integral part of todays technology, they commonly are performant and versatile in integration. Consequently, future applications increasingly aim to harvest the potential of the amorphous state. Establishing its structure-property relationship, however, is inherently challenging using diffraction-based techniques yet is extr...
Article
Amorphous materials are integral part of today´s technology, they commonly are performant and versatile in integration. Consequently, future applications increasingly aim to harvest the potential of the amorphous state. Establishing its structure‐property relationship, however, is inherently challenging using diffraction‐ based techniques yet is ex...
Article
The Front Cover illustrates the conversion of red light from a continuous wave (CW) infrared laser into directed white light when passing through a sample of the inherently amorphous adamantane‐type cluster compound [(StySn)4S6] (sty=styryl). Cover design by Elisa Monte. More information can be found in the Minireview by Stefanie Dehnen, Peter R. S...
Article
The front cover artwork is provided by Stefanie Dehnen, Kerstin Volz, Wolf‐Christian Pilgrim (Philipps University Marburg), Peter R. Schreiner, Sangam Chatterjee, Doreen Mollenhauer, Simone Sanna (Justus Liebig University Giessen), and Nils W. Rosemann (Karlsruhe Institute of Technology). The image illustrates the conversion of red light from a con...
Article
Full-text available
Two photoactive iron N -heterocyclic carbene complexes $${[\hbox {Fe}^{{{\rm{II}}}}(\hbox {btz})_2(\hbox {bpy})]^{2+}}$$ [ Fe II ( btz ) 2 ( bpy ) ] 2 + and $${[\hbox {Fe}^{{\rm{III}}}(\hbox {btz})_3]^{3+}}$$ [ Fe III ( btz ) 3 ] 3 + , where btz is 3,3’-dimethyl-1,1’-bis(p-tolyl)-4,4’-bis(1,2,3-triazol-5-ylidene) and bpy is 2,2’-bipyridine, have be...
Article
Full-text available
A new generation of octahedral iron(II)-N-heterocyclic carbene (NHC) complexes, employing different tridentate C^N^C ligands, has been designed and synthesized as earth-abundant photosensitizers for dye sensitized solar cells (DSSCs) and related...
Article
Full-text available
Molecular compounds of the general formula [(RT) 4 E 6 ] (R = organic or organometallic substituent; T = C, Si, Ge, Sn; E = CH 2 , S, Se), hence adamantane derivatives and inorganic‐organic hybrid compounds based on a heteroadamantane structure, were shown to exhibit non‐linear optical response upon radiation with a continuous‐wave near‐infrared la...
Article
Full-text available
The photofunctionality of the cobalt–hexacarbene complex [Co(III)(PhB(MeIm)3)2]⁺ (PhB(MeIm)3 = tris(3-methylimidazolin-2-ylidene)(phenyl)borate) has been investigated by time-resolved optical spectroscopy. The complex displays a weak (Φ ∼ 10–4) but remarkably long-lived (τ ∼ 1 μs) orange photoluminescence at 690 nm in solution at room temperature f...
Article
Full-text available
Despite a few reports of photoluminescent and strongly photo-oxidizing transition metal complexes with a d⁵ electronic configuration, the photophysics and photochemistry of this class of transition metal complexes have largely remained unexplored. Recent investigations of earth-abundant iron(III) N-heterocyclic carbene (NHC) complexes have demonstr...
Article
Full-text available
A homoleptic organometallic Fe(IV) complex that is stable in both solution and in the solid state at ambient conditions has been synthesized and isolated as [Fe(phtmeimb) 2 ](PF 6 ) 2 (phtmeimb = [phenyl(tris(3‐methylimidazolin‐2‐ylidene))borate] – ). This Fe(IV) N ‐heterocyclic carbene (NHC) complex was characterized by 1 H NMR, HR‐MS, elemental a...
Article
Full-text available
Photoinduced bimolecular charge transfer processes involving an iron(III) N-heterocyclic carbene (FeNHC) photosensitizer [Fe(phtmeimb)2]+ (with phtmeimb being [phenyl(tris(3-methylimidazol-1-ylidene))borate])- and triethylamine as well as N,N-dimethylaniline donors have been studied using optical spec-troscopy. The full photocycle of charge separat...
Article
Full-text available
Earth-abundant first row transition metal complexes are important for the development of large-scale photocatalytic and solar energy conversion applications. Coordination compounds based on iron are especially interesting, as iron is the most common transition metal element in the Earth’s crust. Unfortunately, iron-polypyridyl and related tradition...
Article
Full-text available
We present the first experimental study of the frontier orbitals in an ultra-thin film of the novel hexa-carbene photosensitizer [Fe(btz)³]³⁺, where btz is 3,3′-dimethyl-1,1′-bis(p-tolyl)-4,4′-bis(1,2,3-triazol-5-ylidene). Resonant photoelectron spectroscopy (RPES) was used to probe the electronic structure of films where the molecular and oxidativ...
Article
Full-text available
Ultrafast dynamics of photoinduced charge transfer processes in light-harvesting systems based on Earth-abundant transition metal complexes is of current interest for the development of molecular devices for solar energy conversion applications. A combination of ultrafast spectroscopy and first principles quantum chemical calculations of a recently...
Article
Heterostructures of pentacene (PEN) and buckminsterfullerene (C60) are frequently attracting scientific interest as a well-defined small-molecule model system for the study of internal interfaces between two organic semiconductors. They are prototypical representatives forming a donor-acceptor combination for studies of fundamental optoelectronic p...
Article
Iron’s abundance and rich coordination chemistry are potentially appealing features for photochemical applications. However, the photoexcitable charge-transfer (CT) states of most Fe complexes are limited by picosecond or sub-picosecond deactivation through low-lying metal centered (MC) states, resulting in inefficient electron transfer reactivity...
Article
The influence of the atom source operating parameters on the structural and optical properties of In xGa 1 - xN/GaN nanowires (NWs) grown by plasma-assisted molecular beam epitaxy is investigated. Electron microscopy and photoluminescence spectroscopy reveal a change of the NW tip morphology and an enhancement of the local indium incorporation with...
Article
The vast optical nonlinearity of 1,3,5,7‐tetraphenyladamantane (AdPh4) enables efficient frequency conversion. The observed spectrum depends heavily on the material's habitus. In particular, it shows nonlinear white‐light generation when its powder form is irradiated in the near‐infrared, similar to an analogous organotin sulfide cluster [(PhSn)4S6...
Article
We report that reactions of the binary organotin sulfide cluster [(R(1)Sn)3S4]Cl [A; R(1) = CMe2CH2C(O)Me] with gold(I) phosphane complexes yield discrete ternary complexes [(R(1)Sn)2(AuPMe3)2S4] (1) and [(R(2)Sn)2(AuPMe3)2S4] [2; R(2) = CMe2CH2C(NNH2)Me], which are related to recently published complexes [(R(1,2)Sn)2(AuPPh3)2S4] (B and C). Further...
Article
Dilute bismide Ga(PAsBi)-based structures are promising candidates for highly efficient optoelectronic applications, like the 1 eV sub-cell in multi-junction solar cells or the active region in infra-red laser diodes. The band gap can be tuned independently from the lattice constant, which theoretically enables the deposition of lattice-matched lay...
Article
Carrier multiplication by singlet exciton fission enhances photovoltaic conversion efficiencies in organic solids. This decay of one singlet exciton into two triplet states promises to overcome the Shockley-Queisser limit as up to two electrons may be harvested per absorbed photon. Intermolecular coupling is deemed mandatory for both, singlet excit...
Article
We studied the electron transfer from excitons in adsorbed indoline dye layers across the organic-inorganic interface. The hybrids consist of indoline derivatives on the one hand and different inorganic substrates (TiO2, ZnO, SiO2(0001), fused silica) on the other. We reveal the electron transfer times from excitons in dye layers to the organic-ino...
Article
Highly directional white-light generation was recently reported for the organotin sulfide cluster [(StySn)4S6] (Sty = para-styryl). This effect was tentatively attributed to the amorphous nature of the material in combination with the specific combination of an inversion symmetry-free T/E cluster core (T = tetrel, E = chalcogen) with the attachment...
Article
Hydrazino-benzothiazole and 2-furaldehyde diethyl acetale were connected to complementarily functionalized tin sulfide clusters, with the coupling of an acetale to a hydrazine-functionalized cluster being without precedence so far. Neither ethers nor an N,S combination of heteroatoms had so far been present in the ligand shell of tetrelchalcogenide...
Article
Full-text available
We studied the electron transfer from excitons in adsorbed indoline dye layers across the organic-inorganic interface. The hybrids consist of indoline derivatives on the one hand and different inorganic substrates (TiO$_2$, ZnO, SiO$_2$(0001), fused silica) on the other. We reveal the electron transfer times from excitons in dye layers to the organ...
Article
Für die Umwandlung von Licht einer Wellenlänge, wie es etwa von Lasern abgestrahlt wird, in Licht mit einem breiten Wellenlängenbereich benötigt man normalerweise aufwendig herzustellende Glasfasern oder Kristalle und gepulste oder sehr leistungsstarke Laser, die entsprechend groß und teuer sind. In einer Kooperation unserer Gruppen an den Universi...
Article
Tailored light sources have greatly advanced technological and scientific progress by optimizing the emission spectrum or color and the emission characteristics. We demonstrate an efficient spectrally broadband and highly directional warm-white-light emitter based on a nonlinear process driven by a cheap, low-power continuous-wave infrared laser di...
Article
The excitonic transitions of the type-II (GaIn)As/Ga(AsSb) gain medium of a "W"-laser structure are characterized experimentally by modulation spectroscopy and analyzed using microscopic quantum theory. On the basis of the very good agreement between the measured and calculated photoreflectivity, the type-I or type-II character of the observable ex...
Article
Full-text available
This article1 reports the X-ray diffraction-based structural characterization of the α12 multilayer structure SiGe2Si2Ge2SiGe12 [d’Avezac, Luo, Chanier & Zunger (2012 ▶). Phys. Rev. Lett. 108, 027401], which is predicted to form a direct bandgap material. In particular, structural parameters of the superlattice such as thickness and composition as...
Conference Paper
The dynamics of photoexcited carriers are studied in model pentacene-fullerene heterojunctions revealing signatures associated with charge-transfer states. The long lifetime of the higher-energy signature indicates robustness to non-radiative relaxation or carrier extraction mechanisms.
Article
We report the synthesis of the mixed-valence cluster [(R(5)Sn(IV))6Sn(III)2S12] [1; R(5) = CMe2CH2C(O)Me] under optimization of the reaction conditions. A new crystalline form of 1 in the orthorhombic space group Pbca was found at 250 K, which undergoes crystal transformation into the known monoclinic one at lower temperature. Further, we have stud...
Article
Recently, we reported on ferrocenyl-decorated Sn/S clusters; herein, we present the extension of our investigations by attachment of ruthenocenyl units to an according cluster skeleton. The latter was realized upon improvement of the synthesis of acetylruthenocene, its conversion to a hydrazone derivative, and the subsequent reaction with a keto-fu...
Article
Full-text available
We report on electrostatic screening of polarization-induced internal electric fields in AlN/GaN nanowire heterostructures with Germanium-doped GaN nanodiscs embedded between AlN barriers. The incorporation of Germanium at concentrations above $10^{20}\,\text{cm}^{-3}$ shifts the photoluminescence emission energy of GaN nanodiscs to higher energies...
Article
The photoluminescence quantum efficiencies of a series of Ga(N,As,P)/GaP multiple quantum wells are analyzed. The external quantum efficiencies are derived from the absorbed and the emitted light intensities measured using an integrating sphere mounted inside a closed-cycle helium cryostat. By taking into account the device layer sequences as well...

Network

Cited By