Molecular-scale interface engineering of nanocrystalline titania by co-adsorbents for solar energy conversion.
The use of mixed self-assembled monolayers, combining hydrophobic co-adsorbents with the sensitizer, has been demonstrated to enhance the efficiency of dye-sensitized solar cells (DSCs). Herein, the influence of the anchoring groups of the co-adsorbents on the performance of the DSCs is carefully examined by selecting two model molecules: neohexyl phosphonic acid (NHOOP) and bis-(3,3-dimethyl-butyl)-phosphinic acid (DINHOP). The effect of these co-adsorbents on the photovoltaic performance (J-V curves, incident photon-to-electron conversion efficiency) is investigated. Photoelectron spectroscopy and electrochemical impedance spectroscopy are performed to assess the spatial configuration of adsorbed dye and co-adsorbent molecules. The photoelectron spectroscopy studies indicate that the ligands of the ruthenium complex, containing thiophene groups, point out away from the surface of TiO(2)  in comparison with the NCS group.
Michael Grätzel Center for Mesoscopic Solar Cells, College of Optoelectronic Science and Engineering, Huazhong University of Science and Technology, Wuhan, PR China.
Mingkui
M
Wang
Stefan
S
Plogmaker
Robin
R
Humphry-Baker
Peter
P
Pechy
Håkan
H
Rensmo
Shaik M
SM
Zakeeruddin
Michael
M
Grätzel
D000327:Adsorption; D004738:Engineering / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D012993:Solar Energy; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
C009495:titanium dioxide; D014025:Titanium