Modification of gate dielectric on the performance of copper (II) phthalocyanine based on organic field effect transistors

Top contact Copper (II) Phthalocyanine (CuPc) based on Organic Field Effect Transistor (OFET) using various dielectrics were fabricated. The bare SiO2 and bilayer Polyvinyl alcohol (PVA)/SiO2 gate insulators with different thickness (50 and 100 nm) onto thin SiO2 layers were used as gate dielectrics. It is found that using bilayer gate dielectrics can improve device performance. The PVA/SiO2 bilayer gate insulator architecture increases the field-effect mobility by 20 times and improves the on/off ratio from 103-104. Also the photosensitivity of device was examined under different light intensities. The photosensitivity CuPc-OFET was found as 10 at a light intensity of 100 mW/cm2 at the off state. This proposes that the CuPc-OFET behaves as a phototransistor.