Udo Bach

Solid-state dye-sensitized mesoporous TiO2 solar cells with high photon-to-electron conversion efficiencies

Solar cells based on dye-sensitized mesoporous films of TiO2 arelow-cost alternatives to conventional solid-state devices. Impressive solar-to-electrical energy conversion efficiencies have been achieved with such films when used in conjunction with liquid electrolytes. Practical advantages may be gained by the replacement of the liquid electrolyte with a solid charge-transport material. Inorganic p-type semiconductors, and organic materials have been tested in this regard, but in all cases the incident monochromatic photon-to-electron conversion efficiency remained low. Here we describe a dye-sensitized heterojunction of TiO2 with the amorphous organic hole-transport material 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenyl-amine)9,9′-spirobifluorene (OMeTAD; refs. 10 and 11). Photoinduced charge-carrier generation at the heterojunction is very efficient. A solar cell based on OMeTAD converts photons to electric current with a high yield of 33%.

Control of dark current in photoelectrochemical (TiO2/I−–I3−) and dye-sensitized solar cells

The ruthenium complex bis-tetrabutylammonium cis-dithiocyanato-N,N-bis-2,2-bipyridine-4-carboxylic acid, 4-carboxylate ruthenium(II), N-719, was found to block the dark current of dye sensitized solar cells (DSC), based on mesoporous TiO2 films deposited on a F-doped tin oxide electrode and the effect was compared to surface treatment by TiCl4 and the introduction of a compact TiO2 blocking layer.

Modification of TiO2 Heterojunctions with Benzoic Acid Derivatives in Hybrid Molecular Solid‐State Devices

Reference LPI-ARTICLE-2000-019View record in Web of Science Record created on 2006-02-21, modified on 2017-05-12

Characterization of hole transport in a new class of spiro-linked oligotriphenylamine compounds

Reference LPI-ARTICLE-2000-035View record in Web of Science Record created on 2006-02-21, modified on 2016-08-08

Concept of dye-sensitized mesoporous solid state heterojunction solar cells

Solar cells based on dye-sensitized mesoporous films of TiO2 are low cost alternatives to inorganic semiconductor devices. Solar energy conversion efficiencies of up to 10% have been achieved with such films when used in conjunction with liquid electrolytes. Practical advantage may be gained by the replacement of the liquid electrolyte with a solid charge transport material and various concepts have been proposed in literature to realize such solid-state dye-sensitized heterojunctions. Recently high incident photon to electric current conversion efficiencies have been achieved with a cell consisting of a dye-derivatized mesoporous TiO2 film contacted by a new organic hole conductor. Photoinduced charge carrier generation shows to be very efficient in such devices, while interfacial charge recombination during charge collection can be revealed as the major loss mechanism. Surface treatments with pyridine derivatives proved to significantly improve the energy conversion efficiency of the device.

Recent developments in sensitized mesoporous heterojunction solar cells

Reference LPI-CHAPTER-2002-008View record in Web of Science Record created on 2006-02-21, modified on 2017-05-12