title: Probing inhomogeneous vibrational reorganization energy barriers of interfacial electron transfer.
abstract: An atomic force microscopy (AFM) and confocal Raman microscopy study of the interfacial electron transfer of a dye-sensitization system, i.e., alizarin adsorbed upon TiO(2) nanoparticles, has revealed the distribution of the mode-specific vibrational reorganization energies encompassing different local sites ( approximately 250-nm spatial resolution). Our experimental results suggest inhomogeneous vibrational reorganization energy barriers and different Franck-Condon coupling factors of the interfacial electron transfer. The total vibrational reorganization energy was inhomogeneous from site to site; specifically, mode-specific analyses indicated that energy distributions were inhomogeneous for bridging normal modes and less inhomogeneous or homogeneous for nonbridging normal modes, especially for modes far away from the alizarin-TiO(2) coupling hydroxyl modes. The results demonstrate a significant step forward in characterizing site-specific inhomogeneous interfacial charge-transfer dynamics.
authors.affiliation: Pacific Northwest National Laboratory, Fundamental Science Division, Richland, Washington 99352, USA.
authors.forename: Duohai
authors.initials: D
authors.lastname: Pan
authors.forename: Dehong
authors.initials: D
authors.lastname: Hu
authors.forename: H Peter
authors.initials: HP
authors.lastname: Lu