The application of Langmuir–Blodgett films of a new asymmetrically substituted phthalocyanine, amino-tri-tert-butyl-phthalocyanine, in diodes and in all organic field-effect-transistors

Amino-tri-tert-butyl-phthalocyanine (AmBuPc) was used as the semiconductor thin layers in model Schottky diode and all organic field-effect transistor (OFET). The diode cell showed a rectifying effect with a rectification ratio of 60 at ±3.2 V. The ideality factors were 1.38 in the low voltage region and 3.09 in the high voltage region, respectively. The results of OFET proved that AmBuPc Langmuir–Blodgett (LB) films could be used as the semiconducting layer of OFET, and the OFET could function as a p-channel accumulation device. From the OFET electrical characteristics, the channel carrier mobility is calculated to be about 5.2×10−6 cm2 V−1 s−1, which is higher than that of vacuum-deposited film OFET (7.8×10−7 cm2 V−1 s−1) utilizing the same polymer. This phenomenon can be explained as the highly ordered structure of AmBuPc molecules in the LB films. This suggests that a wide conduction channel is able to form in this all organic device, which provides a new method to simplify the fabrication process of OFET and improve their properties.