Enhancing the Efficiency and Charge Transport Characteristics of Dye-Sensitized Solar Cells by Adding Graphene Nanosheets to TiO2 Working Electrodes. (20th May 2015)

• Record Type: Journal Article
• Authors: Tsai, Chih-Hung; Fei, Po-Hsi; Wu, Wei-Chien
• Is Part Of: Electrochimica acta. Volume 165(2015)
• Page Start: 356
• Page End: 364
• Publication Date: 2015-05-20
• Subjects: DSSCs -- TiO2 -- working electrode -- graphene nanosheets -- charge transport; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2015.02.241
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: In this study, TiO2 -GN nanocomposite working electrodes were fabricated by adding graphene nanosheets (GNs) to TiO2 thin-film working electrodes. The influence of the thickness of the TiO2 thin-film working electrodes on the efficiency and charge transport characteristics of the corresponding dye-sensitized solar cells (DSSCs) was investigated. A GN solution was spin-coated onto the TiO2 thin films, which were then sintered at 100 °C in order to fabricate TiO2 -GN working electrodes. The characteristics of various working electrodes were analyzed via scanning electron microscopy, atomic force microscopy, surface profilometry, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and Raman spectroscopy. Moreover, the DSSCs fabricated from these working electrodes were characterized via current density-voltage, incident photo-to-current conversion efficiency, electrochemical impedance spectroscopy, intensity-modulated photocurrent spectroscopy, and intensity-modulated photovoltage spectroscopy measurements. The results indicate that adding GNs to TiO2 thin films can enhance the electron transport rate and charge collection efficiency in TiO2 -GN working electrodes, and thereby increase the power conversion efficiency of DSSCs. As such, DSSCs containing the TiO2 -GN working electrodes exhibited an efficiency of 8.07%, which is 24.3% higher than that (6.49%) of the DSSCs containing conventional TiO2 working electrodes.