Pentacene-based low voltage organic field-effect transistors with anodized Ta2O5 gate dielectric

Pentacene-based low voltage organic field-effect transistors were realized using an anodized Ta2O5 gate dielectric. The Ta2O5 gate dielectric layer with a surface roughness of 1.3 A was obtained by anodizing an e-beam evaporated Ta film. The device exhibited values of saturation mobility, threshold voltage, and I-on/I-off ratio of 0.45 cm(2)/V s, 0.56 V, and 7.5x10(1), respectively. The gate leakage current was reduced by more than 70% with a hexamethyldisilazane (HMDS) treatment on the Ta2O5 layer. The HMDS treatment also resulted in enhanced mobility values and a larger pentacene grain size.