TY - JOUR
T1 - Photophysical Processes Occurring in a Zn-phthalocyanine in Ethanol Solution and on TiO2 Nanostructures
AU - Iagatti, Alessandro
AU - Doria, Sandra
AU - Marcelli, Agnese
AU - Angelini, Nicola
AU - Notarantonio, Sara
AU - Paoletti, Anna Maria
AU - Pennesi, Giovanna
AU - Rossi, Gentilina
AU - Zanotti, Gloria
AU - Calogero, Giuseppe
AU - Foggi, Paolo
N1 - Publisher Copyright:
© 2015 American Chemical Society.
PY - 2015/8/12
Y1 - 2015/8/12
N2 - The photophysics of 9(19),16(17),23(24)-tri-tert-butyl-2-[ethynyl-(4-carboxymethyl)phenyl] phthalocyaninatozinc(II) (ZnPc) in solution and adsorbed on TiO2 and ZrO2 nanoparticle films is characterized by stationary and time-resolved spectroscopies in the subpicosecond to nanosecond time interval. The comparison between the solution and the solid substrate data allows us to identify different pathways of the energy and electron relaxation. On the solid substrate, the presence of H-aggregates adds a further nonradiative deactivation channel competing with the charge injection into the TiO2-conducting band, thus providing an explanation of the reduced efficiency of the charge transfer processes. The comparison between the kinetics recorded after excitation of the S0-S2 transition and those recorded after excitation of the S0-S1 transition provides an estimate of the internal conversion between S2 and S1 which occurs very efficiently and on an ultrafast (<50 fs) time scale. The ground-state recovery characterized by the decay of the bleaching band in the transient spectra slows down in TiO2 samples and is taken as evidence of the charge injection in this kind of sample.
AB - The photophysics of 9(19),16(17),23(24)-tri-tert-butyl-2-[ethynyl-(4-carboxymethyl)phenyl] phthalocyaninatozinc(II) (ZnPc) in solution and adsorbed on TiO2 and ZrO2 nanoparticle films is characterized by stationary and time-resolved spectroscopies in the subpicosecond to nanosecond time interval. The comparison between the solution and the solid substrate data allows us to identify different pathways of the energy and electron relaxation. On the solid substrate, the presence of H-aggregates adds a further nonradiative deactivation channel competing with the charge injection into the TiO2-conducting band, thus providing an explanation of the reduced efficiency of the charge transfer processes. The comparison between the kinetics recorded after excitation of the S0-S2 transition and those recorded after excitation of the S0-S1 transition provides an estimate of the internal conversion between S2 and S1 which occurs very efficiently and on an ultrafast (<50 fs) time scale. The ground-state recovery characterized by the decay of the bleaching band in the transient spectra slows down in TiO2 samples and is taken as evidence of the charge injection in this kind of sample.
UR - http://www.scopus.com/inward/record.url?scp=84940858388&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.5b04978
DO - 10.1021/acs.jpcc.5b04978
M3 - Article
AN - SCOPUS:84940858388
SN - 1932-7447
VL - 119
SP - 20256
EP - 20264
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 35
ER -