An organic field effect transistor includes a channel structure having a photoalignment layer and an organic semiconductor layer disposed directly over the photoalignment layer, where a charge carrier mobility varies along a thickness direction of the channel structure. The channel structure may define an active area between a source and a drain of the transistor and may include alternating layers of at least two photoalignment layers and at least two organic semiconductor layers. Each photoalignment layer is configured to influence an orientation of molecules within an overlying organic semiconductor layer and hence impact the mobility of charge carriers within the device active area while also advantageously decreasing the OFF current of the device.