Linked Life Data

18597434

Source:http://linkedlifedata.com/resource/pubmed/id/18597434

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
27
pubmed:dateCreated
2008-7-3
pubmed:abstractText
Electron transfer (ET) dynamics at molecule-metal interfaces plays a key role in various fields as surface photochemistry or the development of molecular electronic devices. The bare transfer process is often described in terms of tunneling through an interfacial barrier that depends on the distance of the excited electron to the metal substrate. However, a quantitative characterization of such potential barriers is still lacking. In the present time-resolved two-photon photoemission (2PPE) study of amorphous NH 3 layers on Cu(111) we show that photoinjection of electrons is followed by charge solvation leading to the formation of a transient potential barrier at the interface that determines the ET to the substrate. We demonstrate that the electrons are localized at the ammonia-vacuum interface and that the ET rate depends exponentially on the NH 3 layer thickness with inverse range parameters beta between 1.8 and 2.7 nm (-1). Systematic analysis of this time-resolved and layer thickness-dependent data finally enables the determination of the temporal evolution of the interfacial potential barrier using a simple model description. We find that the tunneling barrier forms after tau E = 180 fs and subsequently rises more than three times faster than the binding energy gain of the solvated electrons.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Jul
pubmed:issn
1520-5126
pubmed:author
pubmed:issnType
Electronic
pubmed:day
9
pubmed:volume
130
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8797-803
pubmed:year
2008
pubmed:articleTitle
Ultrafast electron transfer dynamics at NH3/Cu(111) interfaces: determination of the transient tunneling barrier.
pubmed:affiliation
Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, 14195 Berlin, Germany. staehler@physik.fu-berlin.de
pubmed:publicationType
Journal Article