Dresden 2006 – scientific programme

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CPP: Chemische Physik und Polymerphysik

CPP 23: POSTER Functional Organic Thin Films

CPP 23.54: Poster

Thursday, March 30, 2006, 17:00–19:00, P2

Nanoporous TiO_2 / polyelectrolyte films — •Rolf Kniprath and Stefan Kirstein — Humboldt University of Berlin

Porous TiO_2 films are a prerequisite for the fabrication of efficient dye-sensitized solar cells (DSSCs). They are used as an electrode and for sufficient absorption of light a very rough and highly porous TiO_2 surface is desired. In this work we report on the preparation and characterization of thin porous films of TiO_2 by alternate adsorption of TiO_2 nanoparticles and various polyelectrolytes from aqueous solutions. It is found that the structure of the films depends on the polyelectrolyte used and the preparation method. Besides surface roughness the porousity is determined by adsorption / desorption of dye molecules. The current transport through the films is investigated by measuring the current voltage characteristics of ITO/TiO_2/Au structures. The samples behave like Schottky diodes and it will be shown that the energy barriers at the Au / TiO_2 interface depends on the film structure.