Tuning the Interfacial Area and Porosity of TiO2 Film for Enhanced Light Harvesting in DSSC

Pyrene is used as the template material in the preparation of porosity in TiO2 films. Pores are created in the TiO2 film, using a range of pyrene amounts (0, 2, 3, 4 wt%), to increase the light harvesting efficiency and electron charge capabilities at the TiO2 film/dye/electrolyte interface. The specific surface area of the TiO2 film increases from 49.2 to 115.8 m2 g−1 as the porosity are created with 3% pyrene added TiO2 film (TiO2-pyrene-3). The pore volume of TiO2-pyrene-3 is 0.35 cm3 g−1. The charge transfer of TiO2-pyrene-3 based dye-sensitized solar cell (DSSC) is faster than the other TiO2 films. For TiO2-pyrene-3, the electron transport time is 4.19 ms and the electron recombination time is 34.82 ms. The diffusion coefficient is 8.36 × 10−5 cm2 s−1 for TiO2-pyrene-0 and increases to 1.39 × 10−4 cm2 s−1 for TiO2-pyrene-3. TiO2-pyrene-3 has the highest solar conversion efficiency of 7.58%, an increase of 11.47% over that of TiO2-pyrene-0, 6.80%.