Enhancing the light conversion efficiency of dye-sensitized solar cells using nanochannel TiO2 prepared by spray pyrolysis

To enhance the photoelectric conversion efficiency of dye-sensitized solar cells (DSSCs), micron-size nanochannel TiO2 particles were prepared by spray pyrolysis employing a triblock copolymer as a pore former. The as-prepared nanochannel TiO2 was used to fabricate DSSC photoelectrodes, increasing the active area of TiO2/dye/electrolyte for improving charge transfer. Field emission scanning electron microscopy, transmission electron microscopy, and Brunauer-Emmett-Teller analyses were performed to determine the morphologies and characteristic properties (e.g., porosity) of TiO2 particles with nanochannels obtained for various copolymer amounts. The synthesized TiO2 was made into a paste and applied to DSSC photoelectrodes, resulting in a substantially increased photoconversion efficiency (7.76%) compared to that of a copolymer-free TiO2-based DSSC (3.55%). The amounts of impregnated dye in TiO2-based photoelectrode films prepared using various copolymer amounts were compared using UV-vis absorbance analysis, being substantially increased by triblock copolymer addition. (C) 2017 Published by Elsevier Ltd.This work was supported by the research grant of the Korea Institute of Industrial Technology