Electrospun TiO2 Nanorod Based Dye-Sensitized Solar Cells with High Efficiency
Dye-sensitized solar cells are one of the promising candidates for the next generation of solar cells because of their simple structure with relatively high conversion efficiencies. For a high performance DSSC requires highly nanocrystalline TiO2 electrode with large surface areas and the electrolyte penetrates the porous film all the way to the back-contact. Therefore, we have introduced the electrospinng technique. TiO2 fibers were electrospun directly onto FTO glass substrate from the mixed solution containing poly(vinyl acetate) and titanium(IV) n- propoxide with acetic acid as a catalyst for sol-gel reaction in DMF. To fabricate the electrode used in the DSSC, the electrospun TiO2 web is pressed directly between preheated plates at a temperature, 120oC. It have made one dimentional highly nanocrystalline TiO2 nanorod electrode with lengths of 60-100nm and diameter of 15nm. The detailed morphology was observed by the field emission scanning electron microscopy (FE-SEM) and high resolution transmission electron microcopy (HR-TEM). The calcined nanorods were fully crystalline with the anatase (101) crystal plane comprising most of the surface. The electrospun nanorod film contains about 23% more absorbed dye molecule and 40% more porosity than nanoparticle film. As a result, DSSCs based on liquid electrolytes, the energy conversion efficiency of 11.1% has been achieved. Also the porous structure of the electrospun TiO2 nanorod-based DSSCs was found to be efficiently penetrated by a viscous PVDF based quasi-solid state electrolyte, the energy efficiency obtained 8.03%.
| Liquid Electrolyte | Quas-isolid electrolyte | |
| Voc | 0.770 | 0.744 |
| Jsc(mA/cm2) | 21.07 | 18.11 |
| FF(%) | 68.4 | 59.58 |
| EFF(%) | 11.09 | 8.03 |