| Abstract: | We develop a dual porous(DP) TiO_2 film for the electron transporting layer(ETL) in carbon cathode based perovskite solar cells(C-PSCs). The DP TiO_2 film was synthesized via a facile PS-templated method with the thickness being controlled by the spin-coating speed. It was found that there is an optimum DP TiO_2 film thickness for achieving an effective ETL, a suitable perovskite/TiO_2 interface, an efficient light harvester and thus a high performance C-PSC. In particular, such a DP TiO_2 film can act as a scaffold for complete-filling of the pores with perovskite and for forming high-quality perovskite crystals that are seamlessly interfaced with Ti_O2 to enhance interfacial charge injection. Leveraging the unique advantages of DPTiO2 ETL, together with a dense-packed and pinhole-free TiO_2 compact layer, PCE of the C-PSCs has reached 9.81% with good stability. |
