TY  - JOUR
A1  - Zamponi, Flavio
A1  - Penfold, Thomas J.
A1  - Nachtegaal, Maarten
A1  - Lübcke, Andrea
A1  - Rittmann, Jochen
A1  - Milne, Chris J.
A1  - Chergui, Majed
A1  - van Bokhoven, Jeroen A.
T1  - Probing the dynamics of plasmon-excited hexanethiol-capped gold nanoparticles by picosecond X-ray absorption spectroscopy
JF  - physical chemistry, chemical physics : PCCP
N2  - Picosecond X-ray absorption spectroscopy (XAS) is used to investigate the electronic and structural dynamics initiated by plasmon excitation of 1.8 nm diameter Au nanoparticles (NPs) functionalised with 1-hexanethiol. We show that 100 ps after photoexcitation the transient XAS spectrum is consistent with an 8% expansion of the Au–Au bond length and a large increase in disorder associated with melting of the NPs. Recovery of the ground state occurs with a time constant of ∼1.8 ns, arising from thermalisation with the environment. Simulations reveal that the transient spectrum exhibits no signature of charge separation at 100 ps and allows us to estimate an upper limit for the quantum yield (QY) of this process to be <0.1.
KW  - TiO2 nanoparticles
KW  - diimine-complexes
KW  - electron-transfer
KW  - supported gold
KW  - visible-light
KW  - water
KW  - surface
KW  - reactivity
KW  - nanoclusters
KW  - excitation
Y1  - 2014
U6  - https://doi.org/10.1039/c4cp03301a
SN  - 1463-9076
SN  - 1463-9084
VL  - 2014
IS  - 16
SP  - 23157
EP  - 23163
ER  - 
TY  - GEN
A1  - Zamponi, Flavio
A1  - Penfold, Thomas J.
A1  - Nachtegaal, Maarten
A1  - Lübcke, Andrea
A1  - Rittmann, Jochen
A1  - Milne, Chris J.
A1  - Chergui, Majed
A1  - van Bokhoven, Jeroen A.
T1  - Probing the dynamics of plasmon-excited hexanethiol-capped gold nanoparticles by picosecond X-ray absorption spectroscopy
N2  - Picosecond X-ray absorption spectroscopy (XAS) is used to investigate the electronic and structural dynamics initiated by plasmon excitation of 1.8 nm diameter Au nanoparticles (NPs) functionalised with 1-hexanethiol. We show that 100 ps after photoexcitation the transient XAS spectrum is consistent with an 8% expansion of the Au–Au bond length and a large increase in disorder associated with melting of the NPs. Recovery of the ground state occurs with a time constant of ∼1.8 ns, arising from thermalisation with the environment. Simulations reveal that the transient spectrum exhibits no signature of charge separation at 100 ps and allows us to estimate an upper limit for the quantum yield (QY) of this process to be <0.1.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 176 
KW  - TiO2 nanoparticles
KW  - diimine-complexes
KW  - electron-transfer
KW  - excitation
KW  - nanoclusters
KW  - reactivity
KW  - supported gold
KW  - surface
KW  - visible-light
KW  - water
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-74492
SP  - 23157
EP  - 23163
ER  - 
TY  - JOUR
A1  - Krivenkov, Maxim
A1  - Golias, Evangelos
A1  - Marchenko, Dmitry
A1  - Sanchez-Barriga, Jaime
A1  - Bihlmayer, Gustav
A1  - Rader, Oliver
A1  - Varykhalov, Andrei
T1  - Nanostructural origin of giant Rashba effect in intercalated graphene
JF  - 2D Materials
N2  - To enhance the spin-orbit interaction in graphene by a proximity effect without compromising the quasi-free-standing dispersion of the Dirac cones means balancing the opposing demands for strong and weak graphene-substrate interaction. So far, only the intercalation of Au under graphene/Ni(111) has proven successful, which was unexpected since graphene prefers a large separation (similar to 3.3 angstrom) from a Au monolayer in equilibrium. Here, we investigate this system and find the solution in a nanoscale effect. We reveal that the Au largely intercalates as nanoclusters. Our density functional theory calculations show that the graphene is periodically stapled to the Ni substrate, and this attraction presses graphene and Au nanoclusters together. This, in turn, causes a Rashba effect of the giant magnitude observed in experiment. Our findings show that nanopatterning of the substrate can be efficiently used for engineering of spin-orbit effects in graphene.
KW  - quasi-free-standing graphene
KW  - Ni(111)
KW  - gold intercalation
KW  - spin-orbit interaction
KW  - nanoclusters
KW  - STM
KW  - DFT
Y1  - 2017
U6  - https://doi.org/10.1088/2053-1583/aa7ad8
SN  - 2053-1583
VL  - 4
IS  - 3
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  -