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Papers by Heinrich Schwoerer

Research paper thumbnail of A compact synchrotron radiation source driven by a laser-plasma wakefield accelerator

Nature Physics, 2008

Ultrashort light pulses are powerful tools for time-resolved studies of molecular and atomic dyna... more Ultrashort light pulses are powerful tools for time-resolved studies of molecular and atomic dynamics. They arise in the visible and infrared range from femtosecond lasers, and at shorter wavelengths, in the ultraviolet and X-ray range, from synchrotron sources and free-electron lasers. Recent progress in laser wakefield accelerators has resulted in electron beams with energies from tens of mega-electron volts (refs

Research paper thumbnail of Effect of Alkyl Side Chain Length on Intra- and Intermolecular Interactions of TerthiopheneIsoindigo Copolymers

Research paper thumbnail of Ultrafast ring-opening and solvent-dependent product relaxation of photochromic spironaphthopyran

Physical Chemistry Chemical Physics

The ultrafast dynamics of unsubstituted spironaphthopyran (SNP) were investigated using femtoseco... more The ultrafast dynamics of unsubstituted spironaphthopyran (SNP) were investigated using femtosecond transient UV and visible absorption spectroscopy in three different solvents and semi-classical nuclear dynamics simulations. The primary ring-opening of...

Research paper thumbnail of Ultrafast Pathways of the Photoinduced Insulator–Metal Transition in a Low‐Dimensional Organic Conductor

Research paper thumbnail of Direct Observation of Charge Injection From CH3 NH3 PbI3−x Cl x to Organic Semiconductors Monitored With sub-ps Transient Absorption Spectroscopy

physica status solidi (b)

Research paper thumbnail of Ultrafast Charge Dynamics in Mixed Cation - Mixed Halide Perovskite Thin Films

Research paper thumbnail of Ultrafast excited state dynamics of a bithiophene-isoindigo copolymer obtained by direct arylation polycondensation and its application in indium tin oxide-free solar cells

Journal of Polymer Science Part B: Polymer Physics

Research paper thumbnail of Special issue on imaging the dynamic structure of matter

Journal of Physics B: Atomic, Molecular and Optical Physics

Research paper thumbnail of Ultrafast Metamorphosis of a Complex Charge-Density Wave

Physical Review Letters, 2016

Modulated phases, commensurate or incommensurate with the host crystal lattice, are ubiquitous in... more Modulated phases, commensurate or incommensurate with the host crystal lattice, are ubiquitous in solids. The transition between such phases involves formation and rearrangement of domain walls and is generally slow. Using ultrafast electron diffraction, we directly record the photoinduced transformation between a nearly commensurate and an incommensurate charge-density-wave phase in 1T-TaS(2). The transformation takes place on the picosecond time scale, orders of magnitude faster than previously observed for commensurate-to-incommensurate transitions. The transition speed and mechanism can be linked to the peculiar nanoscale structure of the photoexcited nearly commensurate phase.

Research paper thumbnail of Ultrafast Metamorphosis of a Complex Charge Density Wave in Tantalumdiselenite

International Conference on Ultrafast Phenomena, 2016

Modulated phases, commensurate or incommensurate with the host crystal lattice, are ubiquitous in... more Modulated phases, commensurate or incommensurate with the host crystal lattice, are ubiquitous in solids. The transition between such phases involves formation and rearrangement of domain walls and is generally slow. Using ultrafast electron diffraction, we directly record the photoinduced transformation between a nearly commensurate and an incommensurate charge-density-wave phase in 1T-TaS(2). The transformation takes place on the picosecond time scale, orders of magnitude faster than previously observed for commensurate-to-incommensurate transitions. The transition speed and mechanism can be linked to the peculiar nanoscale structure of the photoexcited nearly commensurate phase.

Research paper thumbnail of Particle acceleration with lasers

South African Journal of Science, Aug 1, 2008

Research paper thumbnail of Selective generation and control of excited vibrational wave packets in the electronic ground state of K 2

Research paper thumbnail of Enhancement of laser-plasma EUV conversion efficiency by introduction of prepulses

Summaries of Papers Presented at the Lasers and Electro Optics Cleo 02 Technical Diges, Feb 1, 2002

Research paper thumbnail of Physik in ultrakurzen und ultraintensiven Feldern

Research paper thumbnail of Kalpha-radiation from relativistic laser-produced plasmas

Europhysics Letters, 2002

We present systematic investigations on the generation of titanium Kalpha-radiation (E = 4.5 keV)... more We present systematic investigations on the generation of titanium Kalpha-radiation (E = 4.5 keV) from plasmas produced with ultrashort, high-intensity laser pulses. A maximum Kalpha-yield appears at a laser intensity of about 3·1017 W/cm2, corresponding to a plasma electron temperature of a few times the Kalpha photon energy. We observe a second increase in the Kalpha-emission yield at intensities higher

Research paper thumbnail of Identification of different pathways of electron injection in dye-sensitised solar cells of electrodeposited ZnO using an indoline sensitiser

Physical chemistry chemical physics : PCCP, Jan 23, 2016

Charge transfer dynamics in fully operational dye sensitised solar cells consisting of an electro... more Charge transfer dynamics in fully operational dye sensitised solar cells consisting of an electrolyte or organic spiroOMeTAD in contact with a highly porous electrodeposited ZnO film sensitised with a monolayer of the indoline dye DN216 were observed using ultrafast transient absorption spectroscopy. From the temporal evolution of spectral signatures assigned with the help of spectroelectrochemical experiments to the population and depopulation of initial, transient and final states, a model was completed for the multistep injection of photoexcited electrons from the molecular absorber to the ZnO acceptor. Injection was found to occur via three different paths with three characteristic rates: directly from the dye's lowest unoccupied molecular orbital into the ZnO conduction band (200 fs) and via intermediate molecular dominated and surface dominated hybrid states (2 ps and 10 ps, respectively).

Research paper thumbnail of Ultrafast Coherent Control in the Electronic Ground State of a Molecule

Journal of the Chinese Chemical Society, 2000

Research paper thumbnail of Cover Picture: Ultrafast Charge-Transfer Reactions of Indoline Dyes with Anchoring Alkyl Chains of Varying Length in Mesoporous ZnO Solar Cells (ChemPhysChem 5/2015)

ChemPhysChem, 2015

Ultrafast transient absorption measurements open aw indow to photo-induced chargetransfer process... more Ultrafast transient absorption measurements open aw indow to photo-induced chargetransfer processes in fully functional indoline dye sensitized solar cells. On p. 943, H. Schwoerer et al. presentthe effect of systematically modified indoline dyes in the cells on electron injection from dye to semiconductor and detrimental recombination channels, and on the cells macroscopic stability.The cover picture displays one of these cells with an indoline dye attached in the African sunlight, accompanied by afemtosecond transient absorptionlandscape.

Research paper thumbnail of Generation of X-Rays by Intense Femtosecond Lasers

Topics in Applied Physics, 2004

Research paper thumbnail of Experiments with counter-propagating laser pulses at relativistic intensities

Research paper thumbnail of A compact synchrotron radiation source driven by a laser-plasma wakefield accelerator

Nature Physics, 2008

Ultrashort light pulses are powerful tools for time-resolved studies of molecular and atomic dyna... more Ultrashort light pulses are powerful tools for time-resolved studies of molecular and atomic dynamics. They arise in the visible and infrared range from femtosecond lasers, and at shorter wavelengths, in the ultraviolet and X-ray range, from synchrotron sources and free-electron lasers. Recent progress in laser wakefield accelerators has resulted in electron beams with energies from tens of mega-electron volts (refs

Research paper thumbnail of Effect of Alkyl Side Chain Length on Intra- and Intermolecular Interactions of TerthiopheneIsoindigo Copolymers

Research paper thumbnail of Ultrafast ring-opening and solvent-dependent product relaxation of photochromic spironaphthopyran

Physical Chemistry Chemical Physics

The ultrafast dynamics of unsubstituted spironaphthopyran (SNP) were investigated using femtoseco... more The ultrafast dynamics of unsubstituted spironaphthopyran (SNP) were investigated using femtosecond transient UV and visible absorption spectroscopy in three different solvents and semi-classical nuclear dynamics simulations. The primary ring-opening of...

Research paper thumbnail of Ultrafast Pathways of the Photoinduced Insulator–Metal Transition in a Low‐Dimensional Organic Conductor

Research paper thumbnail of Direct Observation of Charge Injection From CH3 NH3 PbI3−x Cl x to Organic Semiconductors Monitored With sub-ps Transient Absorption Spectroscopy

physica status solidi (b)

Research paper thumbnail of Ultrafast Charge Dynamics in Mixed Cation - Mixed Halide Perovskite Thin Films

Research paper thumbnail of Ultrafast excited state dynamics of a bithiophene-isoindigo copolymer obtained by direct arylation polycondensation and its application in indium tin oxide-free solar cells

Journal of Polymer Science Part B: Polymer Physics

Research paper thumbnail of Special issue on imaging the dynamic structure of matter

Journal of Physics B: Atomic, Molecular and Optical Physics

Research paper thumbnail of Ultrafast Metamorphosis of a Complex Charge-Density Wave

Physical Review Letters, 2016

Modulated phases, commensurate or incommensurate with the host crystal lattice, are ubiquitous in... more Modulated phases, commensurate or incommensurate with the host crystal lattice, are ubiquitous in solids. The transition between such phases involves formation and rearrangement of domain walls and is generally slow. Using ultrafast electron diffraction, we directly record the photoinduced transformation between a nearly commensurate and an incommensurate charge-density-wave phase in 1T-TaS(2). The transformation takes place on the picosecond time scale, orders of magnitude faster than previously observed for commensurate-to-incommensurate transitions. The transition speed and mechanism can be linked to the peculiar nanoscale structure of the photoexcited nearly commensurate phase.

Research paper thumbnail of Ultrafast Metamorphosis of a Complex Charge Density Wave in Tantalumdiselenite

International Conference on Ultrafast Phenomena, 2016

Modulated phases, commensurate or incommensurate with the host crystal lattice, are ubiquitous in... more Modulated phases, commensurate or incommensurate with the host crystal lattice, are ubiquitous in solids. The transition between such phases involves formation and rearrangement of domain walls and is generally slow. Using ultrafast electron diffraction, we directly record the photoinduced transformation between a nearly commensurate and an incommensurate charge-density-wave phase in 1T-TaS(2). The transformation takes place on the picosecond time scale, orders of magnitude faster than previously observed for commensurate-to-incommensurate transitions. The transition speed and mechanism can be linked to the peculiar nanoscale structure of the photoexcited nearly commensurate phase.

Research paper thumbnail of Particle acceleration with lasers

South African Journal of Science, Aug 1, 2008

Research paper thumbnail of Selective generation and control of excited vibrational wave packets in the electronic ground state of K 2

Research paper thumbnail of Enhancement of laser-plasma EUV conversion efficiency by introduction of prepulses

Summaries of Papers Presented at the Lasers and Electro Optics Cleo 02 Technical Diges, Feb 1, 2002

Research paper thumbnail of Physik in ultrakurzen und ultraintensiven Feldern

Research paper thumbnail of Kalpha-radiation from relativistic laser-produced plasmas

Europhysics Letters, 2002

We present systematic investigations on the generation of titanium Kalpha-radiation (E = 4.5 keV)... more We present systematic investigations on the generation of titanium Kalpha-radiation (E = 4.5 keV) from plasmas produced with ultrashort, high-intensity laser pulses. A maximum Kalpha-yield appears at a laser intensity of about 3·1017 W/cm2, corresponding to a plasma electron temperature of a few times the Kalpha photon energy. We observe a second increase in the Kalpha-emission yield at intensities higher

Research paper thumbnail of Identification of different pathways of electron injection in dye-sensitised solar cells of electrodeposited ZnO using an indoline sensitiser

Physical chemistry chemical physics : PCCP, Jan 23, 2016

Charge transfer dynamics in fully operational dye sensitised solar cells consisting of an electro... more Charge transfer dynamics in fully operational dye sensitised solar cells consisting of an electrolyte or organic spiroOMeTAD in contact with a highly porous electrodeposited ZnO film sensitised with a monolayer of the indoline dye DN216 were observed using ultrafast transient absorption spectroscopy. From the temporal evolution of spectral signatures assigned with the help of spectroelectrochemical experiments to the population and depopulation of initial, transient and final states, a model was completed for the multistep injection of photoexcited electrons from the molecular absorber to the ZnO acceptor. Injection was found to occur via three different paths with three characteristic rates: directly from the dye's lowest unoccupied molecular orbital into the ZnO conduction band (200 fs) and via intermediate molecular dominated and surface dominated hybrid states (2 ps and 10 ps, respectively).

Research paper thumbnail of Ultrafast Coherent Control in the Electronic Ground State of a Molecule

Journal of the Chinese Chemical Society, 2000

Research paper thumbnail of Cover Picture: Ultrafast Charge-Transfer Reactions of Indoline Dyes with Anchoring Alkyl Chains of Varying Length in Mesoporous ZnO Solar Cells (ChemPhysChem 5/2015)

ChemPhysChem, 2015

Ultrafast transient absorption measurements open aw indow to photo-induced chargetransfer process... more Ultrafast transient absorption measurements open aw indow to photo-induced chargetransfer processes in fully functional indoline dye sensitized solar cells. On p. 943, H. Schwoerer et al. presentthe effect of systematically modified indoline dyes in the cells on electron injection from dye to semiconductor and detrimental recombination channels, and on the cells macroscopic stability.The cover picture displays one of these cells with an indoline dye attached in the African sunlight, accompanied by afemtosecond transient absorptionlandscape.

Research paper thumbnail of Generation of X-Rays by Intense Femtosecond Lasers

Topics in Applied Physics, 2004

Research paper thumbnail of Experiments with counter-propagating laser pulses at relativistic intensities