Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2003-8-12
pubmed:abstractText
Photoacoustic calorimetry (PAC) is used to determine the excited state absorption cross sections in a molecular system showing reverse saturable absorption behavior. PAC experiments on fullerene and fulleropyrrolidine in toluene solutions are performed at 532 nm and 690 nm, with a ns laser source. The PAC signal amplitude displays a superlinear increase when the energy of the applied laser source is increased. This behavior is ascribed to a process of enhanced absorption due to molecules populating the excited electronic states. The PAC signal observed for these chromophores is simulated numerically. The simulations rely on a description of the absorbing molecule as a six-level system, whose molecular parameters (i.e. absorption cross sections and lifetimes) are the ones for a reverse saturable absorber. The time-dependent population in the different energy levels is described through a rate equation system. This kind of model has been widely used by us to reproduce other experimental data such as nonlinear transmittance and Z-scan data. The PAC signal amplitude is the sum of the different contributions to non-radiative relaxation which arise from molecules populating different energy levels. The absorption cross sections for the singlet and triplet excited states of fullerene and fulleropyrrolidine are derived from the simulated PAC signal amplitudes. The values obtained are in good agreement with literature data measured with different techniques.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Jul
pubmed:issn
1474-905X
pubmed:author
pubmed:issnType
Print
pubmed:volume
2
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
801-7
pubmed:year
2003
pubmed:articleTitle
Excited state absorption of fullerenes measured by the photoacoustic calorimetry technique.
pubmed:affiliation
Dept. Phys. Chemistry, University of Padova, Via Loredan 2, 1-35131 Padova, Italy. camilla.ferrante@unipd.it
pubmed:publicationType
Journal Article