화학공학소재연구정보센터
Journal of Power Sources, Vol.241, 647-653, 2013
LiF-doped mesoporous TiO2 as the photoanode of highly efficient dye-sensitized solar cells
This paper reports the doping of nanocrystalline TiO2 with LiF by mechanical grinding and subsequent sintering and the application of LiF-doped TiO2 as the photoanode of highly efficient dye-sensitized solar cells (DSCs). The fluoride ions can dope into the TiO2 matrix as revealed by X-ray photoelectron spectroscopy (XPS). The LiF-doped TiO2 samples are characterized by scanning electron microscopy (SEM), tunneling electron microscopy (TEM), X-ray diffraction (XRD), and UV-visible absorption spectroscopy. Doping of TiO2 with a small amount of LiF can improve the photovoltaic performance of DSCs. At the optimal LiF loading of 0.53 wt% in TiO2, the power conversion efficiency (PCE) of DSCs is enhanced from 7.74% to 8.24% under simulated AM1.5 illumination. The effect of the LiF doping on the photovoltaic performance of DSCs is investigated by electrochemical impedance spectroscopy (EIS) and incident photon conversion efficiency (IPCE) measurements. The improvement in the photovoltaic efficiency is attributed to the facilitation of the electron transport through the TiO2 electrode as a result of the increase in the anatase crystallinity induced by the LiF doping. The enhanced anatase crystallinity also causes a decrease in the charge recombination. (C) 2013 Elsevier B.V. All rights reserved.