σ-π molecular dielectric multilayers for low-voltage organic thin-film transistors

Very thin (2.3-5.5 nm) self-assembled organic dielectric multilayers have been integrated into organic thin-film transistor structures to achieve sub-1-V operating characteristics. These new dielectrics are fabricated by means of layer-by-layer solution phase deposition of molecular silicon precursors, resulting in smooth, nanostructurally well defined, strongly adherent, thermally stable, virtually pinhole-free, organosiloxane thin films having exceptionally large electrical capacitances (up to ≈2,500 nF·cm^-2), excellent insulating properties (leakage current densities as low as 10 ^-9 A·cm^-2), and single-layer dielectric constant (k) of ≈16. These 3D self-assembled multilayers enable organic thin-film transistor function at very low source-drain, gate, and threshold voltages (< 1 V) and are compatible with a broad variety of vapor- or solution-deposited p- and n-channel organic semiconductors.