Organic semiconductor materials have been used in perovskite solar cells as buffer layers. We adopted a rubrene/pentacene bilayer as a new type of buffer layer and deposited lead halide perovskite on top of that by dry process for avoiding possible damages of solvents to the organic buffer layers. Depositing perovskite on rubrene improves power conversion efficiency of perovskite solar cell from 6.49 % to 7.46 %. This improvement can be attributed to the rubrene/pentacene bilayer that realizes a smooth surface and a high coverage of the perovskite film.