Solution processed tetrasubstituted zinc phthalocyanine as an active layer in organic field effect transistors

Spun films of liquid crystalline peripheral-tetrasubstituted zinc (II) phthalocyanine (Pc) derivatives have been employed as active organic semiconducting layers in the fabrication of organic field effect transistors. The Pc molecules in the thin film formulation are stacked perpendicular to the substrate. Values of 1.8×10−4 cm2 V−1 s−1 and 103 were estimated for the field-effect mobility and on/off ratio, respectively, from the hysteresis-free transistor characteristics. The transistor can be switched on and off at a relatively low value of 3.7 V for threshold voltage. The carrier transport is believed to be largely determined by the multidomain Pc film structure.