DEVELOPMENT OF TITANIUM DIOXIDE PHOTOELECTRODE MATERIAL FOR DYE SOLAR CELL

Dye solar cell (DSC) has advantage over other solar generation; high possibilities
for improving parameters, compatible with flexible substrate, lower productions cost
and work even in diffuse light. However, DSC still suffers from low efficiency due to
the competition between electron generation and recombination.
The aim of the study is to develop TiOz photoelectrocle material namely
nanoparticles, aggregates and aggregates/nanoparticles composite that promise better
performance efficiency of DSC. The effect of two critical parameters; percentage of
water in ethanol solution and calcination temperature on the morphology and
microstructure of the synthesized TiOz aggregates have been investigated using SEM,
XRD and BET. TiOz photoelectrode films were prepared by screen printing technique
on FTO glass, dye-coated with N719, and assembled in sandwich configuration with
platinized conducting electrode to form DSC. The performance of the integrated
DSCs was compared based on UV-Vis absorption and I-V characteristic under
simulated AM1.5 sunlight illumination with 100 mW/cm2 light output.
Synthesized TiOz nanoparticles photelectrode materials exhibit an efficiency of
3.545%, while aggregates synthesized with 0.9 vol% of water shows higher efficiency
of 3.915%. The optimum calcination temperature was found to be at 45o·c. Higher
efficiency of over 4% can be achieved by incorporating 20% nanoparticle in
aggregates films synthesized using 0.9 vol% of water content and calcined at 45o·c,
producing well formed spherical aggregates with mean size of 0.45 11m consisting of
15±3 nm of nanocrystallite. The submicron-sized aggregates can induce the light
scattering while nanocrystallites can increase the surface area for dye chemisorption.
The incorporated nanoparticles in aggregates films results in better connectivity thus
improves the transport properties. The breakthrough in hierarchical structured
photoelectrode material could spur the development of higher performance DSC to
challenge the high cost of commercially available silicon-based solar cells.