Study the Effect of Ruthenium Dye Layer on Negative Capacitance in Solar Cells Based on the Nc-TiO<sub>2</sub> Semiconducting Polymer Heterojunction

Abstract

We report the effect of ruthenium dye on negative capacitance of nanocrystalline titanium dioxide/poly(3-hexyl thiophene), nc-TiO 2 /P3HT, heterojunction solar cells. It has been found that the low frequency capacitance reaches a high positive value and then drop to the negative region. In P3HT/Ru-Dye/nc-TiO 2 solar cells, the negative capacitance is observed under very low forward bias condition unlike the negative capacitance in P3HT/ncTiO 2 solar cells. That is attributed to the difference of the concentration of dipole and presence of depletion region at interface between the P3HT and nc-TiO 2 .