The poor crystallinity of rubrene in thin films is an obstacle limiting its practical applications in organic electronics. Here we report a strategy of using 6,13-pentacenequinone (PQ), an easily crystallized insulating molecule, as the template layer to induce the crystallization of rubrene in vacuum-deposited thin film transistors. This strategy relies on the bilayer steps of octadecylphosphonic acid, which play a unique role in modulating the morphology of PQ.