TY  - JOUR
A1  - Schattauer, Sylvia
A1  - Reinhold, Beate
A1  - Albrecht, Steve
A1  - Fahrenson, Christoph
A1  - Schubert, Marcel
A1  - Janietz, Silvia
A1  - Neher, Dieter
T1  - Influence of sintering on the structural and electronic properties of TiO2 nanoporous layers prepared via a non-sol-gel approach
JF  - Colloid and polymer science : official journal of the Kolloid-Gesellschaft
N2  - In this work, a nonaqueous method is used to fabricate thin TiO2 layers. In contrast to the common aqueous sol-gel approach, our method yields layers of anatase nanocrystallites already at low temperature. Raman spectroscopy, electron microscopy and charge extraction by linearly increasing voltage are employed to study the effect of sintering temperature on the structural and electronic properties of the nanocrystalline TiO2 layer. Raising the sintering temperature from 120 to 600 A degrees C is found to alter the chemical composition, the layer's porosity and its surface but not the crystal phase. The room temperature mobility increases from 2 x 10(-6) to 3 x 10(-5) cm(2)/Vs when the sinter temperature is increased from 400 to 600 A degrees C, which is explained by a better interparticle connectivity. Solar cells comprising such nanoporous TiO2 layers and a soluble derivative of cyclohexylamino-poly(p-phenylene vinylene) were fabricated and studied with regard to their structural and photovoltaic properties. We found only weak polymer infiltration into the oxide layer for sintering temperatures up to 550 A degrees C, while the polymer penetrated deeply into titania layers that were sintered at 600 A degrees C. Best photovoltaic performance was reached with a nanoporous TiO2 film sintered at 550 A degrees C, which yielded a power conversion efficiency of 0.5 %. Noticeably, samples with the TiO2 layer dried at 120 A degrees C displayed short-circuit currents and open circuit voltages only about 15-20 % lower than for the most efficient devices, meaning that our nonaqueous route yields titania layers with reasonable transport properties even at low sintering temperatures.
KW  - Nonaqueous sol-gel
KW  - Thin nanocrystalline TiO2 layer
KW  - Solar cells
KW  - Effect of sintering
KW  - Linearly increasing voltage (CELIV)
KW  - Polymer infiltration
KW  - Transport properties titania
KW  - Transient fluorescence
Y1  - 2012
U6  - https://doi.org/10.1007/s00396-012-2708-9
SN  - 0303-402X
VL  - 290
IS  - 18
SP  - 1843
EP  - 1854
PB  - Springer
CY  - New York
ER  -