Gate Dielectric Chemical Structure−Organic Field-Effect Transistor Performance Correlations for Electron, Hole, and Ambipolar Organic Semiconductors

• DOI: 10.1021/ja063290d
• Publication Date: 2006-09-09T10:06:23Z
• Authors: Myung-Han Yoon; Choongik Kim; Antonio Facchetti; Tobin J. Marks
• Keywords: Ambipolar diffusion; Organic semiconductor; Organic field-effect transistor

This study describes a general approach for probing semiconductor-dielectric interfacial chemistry effects on organic field-effect transistor performance parameters using bilayer gate dielectrics. Organic semiconductors exhibiting p-/n-type or ambipolar majority charge transport are grown six different dielectric structures consisting of various spin-coated polymers/HMDS 300 nm SiO(2)/p(+)-Si, and characterized by AFM, SEM, WAXRD, followed electrical characterization. In the case air-sensitive (generally high LUMO energy) n-type semiconductors, surface modifications induce large variations in corresponding OTFT although film morphologies microstructures remain similar. marked contrast, device air-stable p-type is not significantly affected same modifications. Among examined, nonpolar polystyrene coatings SiO(2) having minimal leakage roughness enhance mobilities overlying to as approximately 2 cm(2)/(V s) alpha,omega-diperfluorohexylcarbonylquaterthiophene polystyrene/SiO(2). Electron trapping due silanol carbonyl functionalities at interface identified principal origin mobility sensitivity chemistries energies. Thiophene-based similar dielectrics therefore provide an incisive means probe TFT versus relationships.