The mobilities of the solution-processed n-type organic semiconductor, N,N′-di((Z)-9-octadecene)-3,4,9,10-perylene tetracarboxylic diimide (PTCDI-e), were dramatically improved (up to 30 times) by blending with electron donors. The reason can be assigned to the facilitated charge transport due to the increased stack-ordering and crystallinity of the spin-coated thin films after blending. This provides a new way to enhance the performance of existing organic semiconductors by intentional blending.