Organic thin film transistors with double insulator layers

We have investigated a double-layer structured gate dielectric for the organic thin films transistor (OTFT) with the purpose of improving the performance of the SiO2 gate insulator. A 50 nm PMMA layer was coated on top of the SiO2 gate insulator as organic insulator layer. The results demonstrated that using inorganic/organic compound insulator as the gate dielectric layers is an effective method to fabricate OTFTs with improved electric characteristics and decreased leakage current. Electrical parameters such as carrier mobility and on/off ratio by field effect measurement have been calculated. OTFT based on highly doped Si substrate with a field-effect mobility of 0.004 cm2/V s and on/off ratio of 104 have been obtained.