In this study, P3HT, PEDOT:PSS, and monodispersed colloidal TiO 2 was synthesize by the Grignard metathesis method, oxidative chemical polymerization, and sol–gel procedure, respectively. The prepared P3HT, PEDOT:PSS, and TiO 2 were further applied with phenyl-C61-butyric acid methyl ester (PCBM) to fabricated the Al/Ca/P3HT:PCBM:TiO 2 /PEDOT:PSS/ITO hybrid solar cell by spin-coating and evaporation deposition. The effect of TiO 2 content and annealing temperature on the cell performance was investigated. The results show that optimization of TiO 2 content (20wt%) and annealing temperature (140 °C) can effectively enhance the performance of hybrid solar cell. In the P3HT:PCBM:TiO 2 active layer, PCBM and TiO 2 can absorb more photons from light, but the interface area between the components is also increased. The charge transfer in the P3HT:PCBM:TiO 2 active layer is more efficient, which increases the amount of PL quenching. The increase of surface roughness of active layer may also effectively reduce the charge-transport distance and enhance the internal light scattering and light absorption. The best value of the Voc, Jsc, fill factor, and efficiency for the prepared hybrid solar cell are Voc = 0.53 V, Jsc = 11.38m A/cm2, FF = 55.76, and η = 3.36, respectively.