Document 
Eur. Phys. J. E 26, 73-79 (2008)
DOI: 10.1140/epje/i2007-10292-2
Layered TiO2 :PVK nano-composite thin films for photovoltaic applications
TiO2 :PVK nano-composite thin films
G. Kaune1, W. Wang1, E. Metwalli1, M. Ruderer1, R. Roßner1, S. V. Roth2 and P. Müller-Buschbaum11 Physik-Department, LS E13, TU München, James-Franck-Str. 1, 85747, Garching, Germany
2 HASYLAB at DESY, Notkestr. 85, 22603, Hamburg, Germany
muellerb@ph.tum.de
Received 18 September 2007 / Published online 15 April 2008
Abstract
The influence of the solvent used for spin-coating on the homogeneity of poly(N-vinylcarbazole) (PVK) films is investigated. Homogenous films are obtained only by the use of toluene, solution in tetrahydrofuran (THF) and chloroform results in radially oriented inhomogeneities and films prepared by use of N-methylpyrrolidone and dimethylacetamide show particle formation during spin-coating. Layered nano-composite thin films are prepared by spin-coating a PVK film on top of a nano-structured titanium dioxide ( TiO2 layer. The TiO2 thin films are prepared by a sol-gel process using an amphiphilic copolymer as structure-directing agent. Structural characterisation of the TiO2 :PVK nano-composite films is done by field emission scanning electron microscopy (FESEM) and grazing-incidence small-angle scattering (GISAXS). Bare TiO2 films are probed for comparison. Light is basically only absorbed in the ultraviolet regime and absorption slightly increases upon addition of PVK, which makes the layered TiO2 :PVK nano-composite thin films good candidates for UV photovoltaic devices. Furthermore, absorption remains stable over a period of several days.
PACS61.41.+e - Polymers, elastomers and plastics.
68.55.-a - Thin film structure and morphology.
82.47.Jk - Photoelectrochemical cells, photoelectrochromic and other hybrid electrochemical energy storage devices. Correspondence: G. Kaune
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2008