Deep-UV Curing of Poly(4-Vinyl Phenol) Gate Dielectric for Hysteresis-Free Organic Thin-Film Transistors

A simple method is presented to remedy the hysteresis problem associated with the gate dielectric of poly(4-vinyl phenol) (PVPh), which is widely used for organic transistors. The method involves simple blanket illumination of deep ultraviolet (UV) on the PVPh layer at room temperature. The exposure results in the photochemical transformation of hydroxyl groups in PVPh via the UV/ozone effect. This reduction in the concentration of hydroxyl groups enables one to effectively control the hysteresis problem even when the layer is exposed to moisture. The contrast created in the concentration of hydroxyl groups between the exposed and unexposed parts of PVPh also allows simultaneous patterning of the dielectric layer.