01768nas a2200169   4500008004100000245008600041210006900127260000800196300001600204490000700220520117600227100001901403700001801422700001701440700002601457856011501483       2011                        eng d00aExciton-coupled charge-transfer dynamics in a porphyrin J-aggregate/TiO 2 complex0 aExcitoncoupled chargetransfer dynamics in a porphyrin Jaggregate  cMAR  a3458–34640 v173 a<p>Exciton-coupled charge-transfer (CT) dynamics in TiO2 nanoparticles (NP) sensitized with porphyrin J-aggregates has been studied by femtosecond time-resolved transient absorption spectroscopy. J-aggregates of 5,10,15-triphenyl-20-(3,4-dihydroxyphenyl) porphyrin (TPPcat) form CT complexes on TiO2 NP surfaces. Catechol-mediated strong CT coupling between J-aggregate and TiO2 NP facilitates interfacial exciton dissociation for electron injection into the conduction band of the TiO2 nanoparticle in pulse width limited time (&lt;80 fs). Here, the electron-transfer (&lt;80 fs) process dominates over the intrinsic exciton-relaxation process (J-aggregates: ca. 200 fs) on account of exciton-coupled CT interaction. The parent hole on J-aggregates is delocalized through J-aggregate excitonic coherence. As a result, holes immobilized on J-aggregates are spatially less accessible to electrons injected into TiO2, and thus the back electron transfer (BET) process is slower than that of the monomer/TiO2 system. The J-aggregate/porphyrin system shows exciton spectral and temporal properties for better charge separation in strongly coupled composite systems.</p>1 aVerma, Sandeep1 aGhosh, Amrita1 aDas, Amitava1 aGhosh, Hirendra, Nath  uhttps://library.ncl.res.in/content/exciton-coupled-charge-transfer-dynamics-porphyrin-j-aggregatetio-2-complex