Photovoltaic Efficiencies on Dye-Sensitized Solar Cells Assembled with Graphene-Linked TiO2 Anode Films

To promote the photoelectric conversion efficiency of dye-sensitized solar cells (DSSCs), graphene is introduced as a working electrode with TiO2 in this study, because it has great transparency and very good conductivity. XRD patterns indicate the presence of graphene and TiO2 particles in graphene-linked TiO2 samples. Moreover, TEM pictures also show that the nano-sized TiO2 particles are highly dispersed and welllinked onto the thin layered graphene. On the basis of the UV-visible spectra, the band gaps of TiO2, 1.0 wt % graphene-TiO2, 5.0 wt % graphene-TiO2, and 10.0 wt % graphene-TiO2 are 3.16, 2.94, 2.25, and 2.11 eV, respectively. Compared to pure TiO2, the energy conversion efficiency was enhanced considerably by the application of graphene-linked TiO2 anode films in the DSSCs to approximately 6.05% for 0.1 wt % grapheneTiO2 with N719 dye (10.0 mm film thickness and 5.0 mm × 5.0 mm cell area) under 100 mW/cm 2 of simulated sunlight. The quantum efficiency was the highest when 1.0 wt % of graphene was used. In impedance curves, the resistance was smallest for 1.0 wt % graphene- TiO2-DSSC.

[1]  Zhiyu Jiang,et al.  A green and facile synthesis of TiO2/graphene nanocomposites and their photocatalytic activity for hydrogen evolution , 2012 .

[2]  Jili Wu,et al.  Solvothermal synthesis and characterization of sandwich-like graphene/ZnO nanocomposites , 2010 .

[3]  R. Amal,et al.  Semiconductor/reduced graphene oxide nanocomposites derived from photocatalytic reactions , 2011 .

[4]  J. Tauc,et al.  Amorphous and liquid semiconductors , 1974 .

[5]  Min-Kyeong Yeo,et al.  Photodecomposition of bisphenol A on nanometer-sized TiO2 thin film and the associated biological toxicity to zebrafish (Danio rerio) during and after photocatalysis. , 2006, Water research.

[6]  Xiaoling Yang,et al.  One-pot preparation of graphene/Fe3O4 composites by a solvothermal reaction , 2010 .

[7]  Junwei Zheng,et al.  Triphenylamine-functionalized graphene decorated with Pt nanoparticles and its application in photocatalytic hydrogen production , 2012 .

[8]  Ji-Yeon Chae,et al.  Cubic titanium dioxide photoanode for dye-sensitized solar cells , 2011 .

[9]  Ji-Yeon Chae,et al.  Comparison of the photovoltaic efficiency on DSSC for nanometer sized TiO2 using a conventional sol-gel and solvothermal methods , 2010 .

[10]  D. Y. Kim,et al.  Photovoltaic efficiency on dye-sensitized solar cells (DSSC) assembled using Ga-incorporated TiO2 materials , 2010 .

[11]  Chengyi Hou,et al.  P25-graphene hydrogels: room-temperature synthesis and application for removal of methylene blue from aqueous solution. , 2012, Journal of hazardous materials.

[12]  J. Hoefelmeyer,et al.  TiO2 compact layers prepared by low temperature colloidal synthesis and deposition for high performance dye-sensitized solar cells , 2012 .

[13]  Misook Kang,et al.  Hydrogen production from methanol/water decomposition in a liquid photosystem using the anatase structure of Cu loaded TiO2 , 2007 .

[14]  S. Stankovich,et al.  Synthesis of graphene-based nanosheets via chemical reduction of exfoliated graphite oxide , 2007 .

[15]  Shruti A. Agarkar,et al.  Enhanced DSSC performance with high surface area thin anatase TiO2 nanoleaves , 2011 .

[16]  K. Müllen,et al.  Transparent, conductive graphene electrodes for dye-sensitized solar cells. , 2008, Nano letters.

[17]  Q. Shen,et al.  Photoacoustic and photoelectrochemical characterization of CdSe-sensitized TiO2 electrodes composed of nanotubes and nanowires , 2006 .

[18]  Young-Jin Jung,et al.  Enhanced efficiency of dye-sensitized TiO2 solar cells (DSSC) by doping of metal ions. , 2005, Journal of colloid and interface science.

[19]  Chunhui Xu,et al.  Microwave-assisted covalent modification of graphene nanosheets with chitosan and its electrorheological characteristics , 2011 .