Abstract:
Dye – sensitized solar cells (DSSCs) are promising cost-efficient devices in the
solar energy conversion process. This type of solar cell combines the optical
absorption and charge separation processes by the association of a sensitizer as
photon absorbing material with a wide band gap semiconductor such as TiO2. The
power conversion efficiency of a solar cell depends on the efficiency of light
absorption, charge separation and charge collection processes. Usually, liquid
electrolytes are used in dye-sensitized solar cells. Liquid electrolytes give high
performance to solar cells. However, there are many problems including leakage,
evaporation of the solvent and photodegradation. In order to overcome these
limitations, quasi-solid-state electrolytes are used. But, the efficiencies of the
DSSCs with quasi-solid-state electrolytes are lower than those of DSSCs with
liquid electrolytes. However, gel polymer electrolytes become feasible alternatives
to the liquid electrolytes having improved properties. Polyvinylpyrrolidone (PVP)
based quasi solid-state electrolytes have been synthesized and studied with N719
dye-sensitized solar cells. In order to enhance the ionic conductivity of the gel
electrolyte, TiO2 nanofillers were incorporated and suitable amount of the
nanofiller for efficient electrolyte has been optimized by current – voltage
characterization of the fabricated DSSCs. Gel electrolyte with 0.3% of nanofiller
shows a better efficiency of 2.54% while controlled cell shows an efficiency of
1.43% under the same condition. Overall performance of the electrolyte has been
enhanced by TiO2 nanofillers.
