Quasi-solid state DSSC performance enhancement by bilayer mesoporous TiO₂ structure modification

Quasi-solid state dye-sensitized solar cells (DSSC) having bilayer structure were made by using nanocrystalline anatase-rutile TiO₂ to enhance the photovoltaic performance. The bilayer structures were coated to FTO glass using doctor blade technique with total active area of 0.4 cm². Cyanidin dye extracted from mangosteen pericarp was used as photosensitizer. Bilayer anataseanatase was formed with surface area of 99.9 m²/g and pore volume of 0.23 cc/g while anataserutile structure has surface area of 103.5 m²/g and pore volume of 0.21 cc/g. Overall energy conversion efficiencies under illumination of 10 mW/cm² of 0.461% and 0.1365% were achieved for DSSC employing anatase-anatase and anatase-rutile TiO₂ structure, respectively. Both efficiencies were higher than that of monolayer anatase and rutile TiO₂ structure whose efficiencies in the range of 0.02% to 0.037%. The photocurrent action spectra of bilayer structures performed high efficiency spectrum in the wavelength range of 420 - 480 nm owing to cyanidin effect of dye.