Functionalized multi-wall carbon nanotubes/TiO2 composites as efficient photoanodes for dye sensitized solar cells. Issue 16 (7th April 2016)

• Record Type: Journal Article
• Authors: Benetti, Daniele; Dembele, Kadiatou Therese; Benavides, Jaime; Zhao, Haiguang; Cloutier, Sylvain; Concina, Isabella; Vomiero, Alberto; Rosei, Federico
• Is Part Of: Journal of materials chemistry. Volume 4:Issue 16(2016)
• Page Start: 3555
• Page End: 3562
• Publication Date: 2016-04-07
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c6tc00800c
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : The incorporation of functionalized multi-wall carbon nanotubes into TiO2 mesoporous photoanodes for dye-sensitized solar cells leads to 30% enhancement in photoconversion efficiency of the optimized system. Abstract : We report on the effects of incorporation of different concentrations of carboxyl group (COOH)-functionalized multi-wall carbon nanotubes (F-MWCNTs) into TiO2 active layers for dye-sensitized solar cells (DSSCs). Standard DSSCs with bare TiO2 exhibit a photo-conversion efficiency (PCE) of 6.05% and a short circuit current density ( J sc ) of 13.3 mA cm −2 . The presence of 2 wt% F-MWCNTs in the photoanodes increases the PCE up to 7.95% and J sc up to 17.5 mA cm −2 . The photoanodes were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy. The electrochemical behaviour of the solar cells was investigated by electrochemical impedance spectroscopy (EIS). We attribute the improved performances to the combined effect of increased dye loading and reduced charge recombination (as clarified by dye loading and EIS measurements), due to the conformal coverage of F-MWCNTs, which allows fast and efficient charge collection in operating solar cells. These results can help in improving the PCE in DSSCs in an elegant and straightforward way, minimizing the need of additional steps ( e.g. pre- and post-treatment with TiCl4 ) for photoanode preparation.