title: Passivation of nanocrystalline TiO2 junctions by surface adsorbed phosphinate amphiphiles enhances the photovoltaic performance of dye sensitized solar cells.
abstract: We report a new class of molecular insulators that electronically passivate the surface of nanocrystalline titania films for high performance dye sensitized solar cells (DSC). Using electrical impedance measurements we demonstrate that co-adsorption of dineohexyl bis-(3,3-dimethyl-butyl)-phosphinic acid (DINHOP), along with the amphiphilic ruthenium sensitizer Z907Na increased substantially the power output of the cells mainly due to a retardation of interfacial recombination of photo-generated charge carriers. The use of phosphinates as anchoring groups opens up new avenues for modification of the surface by molecular insulators, sensitizers and other electro-active molecules to realize the desired optoelectronic performance of devices based on oxide junctions.
authors.affiliation: Laboratory for Photonics and Interfaces, Swiss Federal Institute of Technology, CH 1015, Lausanne, Switzerland.
authors.forename: Mingkui
authors.initials: M
authors.lastname: Wang
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Hong
authors.initials: H
authors.lastname: Lin
authors.forename: Peter
authors.initials: P
authors.lastname: Pechy
authors.forename: Shaik M
authors.initials: SM
authors.lastname: Zakeeruddin
authors.forename: Michael
authors.initials: M
authors.lastname: Grätzel