Abstract:

TiO₂ nanopaticle was synthesised by sol-hydrothermal using titanium isopropoxide as the precursor. The effects of synthesis conditions on grain size, crystallinity and phase transformation between phasepure rutile and phase-pure anatase, were analyzed by TEM and XRD. It was revealed that crystal-type, crystallinity and crystal-size (from 10-20nm to 120nm) of TiO₂ nanoparticles could be controlled by the pre-thermal treatment, hydrothermal temperature and concentration of the precursor. A paste, made from the nanoparticles and water, and by a doctor-blade technology which could control the thickness of the film were utilized to make a Dye-Sensitized Solar Cell (DSSC), which achieved a photoelectric conversion efficiency of 7.33%, as a result of the phase-pure anatase, appropriate grain size and favorable crystallinity of the TiO₂ nanoparticles. It exceeded those DSSC’s efficiencies made from the commercial paste or P25 paste.

Key words: dye-sensitized solar cells, nanoparticle TiO₂, crystallinity, grain size