Slot-die coating of sol–gel-based organic–inorganic nanohybrid dielectric layers for flexible and large-area organic thin film transistors

•Slot-die coating is applied to fabricate a large-area and simple dielectric layer of organic thin-film transistors (OTFTs).•Sol-gel-based organic–inorganic (O–I) nanohybrid dielectric layer is deposited on the wafers and plastics substrates (maximum substrate size up to 4 inch) through controlling slot-die coating conditions.•The flexible large-area OTFT arrays with optimum slot-die-coated O-I nanohybrid dielectric layers yield an average field-effect mobility of 0.675 cm2 V−1 s−1 with a low standard deviation of 0.052017 cm2 V−1 s−1.