An energy-economical dye-sensitized solar cell (DSSC) with highly flexible Ti/TiO2 photoanode was developed through a low-temperature process, using a binder-free TiO2 paste. Ti foils, coated with the binder-free TiO2 films were annealed at various temperature. Scanning electron microscopic (SEM) images of the films show uniform, mesoporous and crack-free surface morphologies as well as interpenetrated TiO2 network. DSSCs with binder-free TiO2 films annealed at 450, 350, 250 and 120°C show solar-to-electricity conversion efficiencies (Î·) of 4.33, 4.34, 3.72 and 3.40%, respectively, which are comparable to the efficiency of 4.56% obtained by using a paste with binder and annealing it at 450°C; this observation demonstrates the benefits of a binder-free TiO2 paste for the fabrication of energy-fugal DSSCs. On the other hand, when organic binder was used in the TiO2 paste for film preparation, a drastic deterioration in the cell performance with decreasing annealing temperature is noticed. Laser-induced photo-voltage transient technique is used to estimate the electron lifetime in various Ti/TiO2 films. Electrochemical impedance spectroscopic (EIS) analysis shows that the lower the annealing temperature of the TiO2 coated Ti foil, the larger the charge transfer resistance at the TiO2/dye/electrolyte interface (R ct2).
|Number of pages||10|
|Journal||Progress in Photovoltaics: Research and Applications|
|State||Published - Mar 2012|
- dye-sensitized solar cells
- electrochemical impedance spectroscopy
- semi-transparent Pt counter electrode