Gate dielectric microstructural control of pentacene film growth mode and field-effect transistor performance

The growth of pantacene films of varying thickness on various untreated/polymer-coated SiO₂ gate dielectrics were analyzed by using AFM, XRD, and FET. Tapping mode AFM images were recorded in the initial stages of the film deposition process to assess how the surface chemical functionalization of the bilayer insulator affects pantacene film growth. The mechanism by which the microstructural mobilities of the polymeric gate dielectrics affect pantacene film growth mode, film phase transition, and OTFT response were also discussed. It was reported that the thin-film phase predominates at small thickness, while as the film thickness increases the proportion containing the bulk phase increases. Results show that for optimum semiconductor growth conditions and controlled insulator electrical characteristics, insulator surface chemical characteristics and dielectric constants play only a minor role in pentacene OTFT response.