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

Abstract The slot-die coating method has enormous potential owing to the industrial applicability of its high throughput capability to the large-area fabrication of solution-processed films. Herein, we demonstrated a slot-die-coated sol-gel-based organic–inorganic (O–I) nanohybrid dielectric film for organic thin film transistors (OTFTs) with highly uniform properties, such as thickness, morphology, and electrical insulating characteristics. Through the modification of the solution properties and coating speed conditions, the slot-die coating process was used to successfully fabricate defect-free dielectric films with uniform morphology, ranging from below 50 to 800 nm. Additionally, from the OTFT behavior, we identified the clockwise hysteresis by the insulator bulk for the deposition of thick O–I nanohybrid dielectrics. Based on these analyses, we can produce flexible large-area OTFT arrays with optimum slot-die-coated dielectric layers, showing 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. These results suggest that this printing technology has considerable potential in the manufacturing of flexible organic electronic devices that require industrial reliability and large-area processing.