Dye-Sensitized Solar Cells with P3HT/Fullerene Derivatives

We have focused on the fabrications and photovoltaic properties of dye-sensitized solar cell (DSSC) devices using soluble fulleropyrrolidine derivatives, N-methyl-2-phenylalkoxy-3,4-fulleropyrrolidine (MPFP-14 and MPFP-16), as a charge transfer material (CTM). The power conversion efficiency of DSSC with them were 3.34~3.55 % which higher value than 2.6 % of DSSC without CTM under AM 1.5 (100 mA/cm²). This result was caused by HOMO level of MPFP-14 or MPFP-16 that higher than redox potential of iodine redox couple, and lower than work function of Pt counter electrode. However, DSSC device using poly(3-hexyl thiophene) (P3HT) has the lowest efficiency as 0.67 % because the recombination of electron and hole may occur through the blocking of hole transfer, and it cause the decrease of J_sc and FF of DSSC device. To overcome this problem, DSSCs with P3HT/CTM blend layers using CTM such as MPFP-14, MPFP-16, PCBM, or C₆₀ were investigated and it has resulted in the increase in efficiency of 2.18~3.41%