Passivation of nanocrystalline TiO2 junctions by surface adsorbed phosphinate amphiphiles enhances the photovoltaic performance of dye sensitized solar cells

Wang, Mingkui; Li, Xin; Lin, Hong; Pechy, Peter; Zakeeruddin, Shaik M.; Grätzel, Michael

Passivation of nanocrystalline TiO2 junctions by surface adsorbed phosphinate amphiphiles enhances the photovoltaic performance of dye sensitized solar cells

Type

Article

Authors

Wang, Mingkui
Li, Xin

Lin, Hong
Pechy, Peter
Zakeeruddin, Shaik M.
Grätzel, Michael

Date

2009

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. © 2009 The Royal Society of Chemistry.

Citation

Wang M, Li X, Lin H, Pechy P, Zakeeruddin SM, et al. (2009) Passivation of nanocrystalline TiO2 junctions by surface adsorbed phosphinate amphiphiles enhances the photovoltaic performance of dye sensitized solar cells. Dalton Trans: 10015. Available: http://dx.doi.org/10.1039/b908673k.

Acknowledgements

This work was supported by the Stanford University KAUST center of Excellency and a grant from the United State Airforce. X. Li thanks the Chinese National Natural Science Foundation (50672041) for a grant to support a 6 months leave at the EPFL during which time his contribution to this work was performed. We thank Dr. Robin Humphry-Baker for fruitful discussions and Pascal Comte for the TiO2 film preparations.