Solution-processed high-k photopatternable polymers for low-voltage electronics

Abstract

High dielectric constant (k) polymers have been widely explored for flexible, low-power-consumption electronic devices. In this work, solution-processable high-k polymers were designed and synthesized by ultraviolet (UV) triggered crosslinking at a low temperature (60 °C). The highly crosslinked network allows for high resistance to organic solvents and high breakdown strength over 2 MV cm⁻¹. The UV-crosslinking capability of the polymers enables them to achieve a high-resolution pattern with a feature size down to 1 μm. Further investigation suggests that the polar cyano pendants in side chains are responsible for increasing the dielectric constant up to 10 in a large-area device array, thereby contributing to a low driving voltage of 5 V and high field-effect mobility exceeding 20 cm² V⁻¹ s⁻¹ in indium gallium zinc oxide (IGZO) thin-film transistors (TFTs). In addition, the solution-processable high-k dielectric polymers were utilized to fabricate flexible low-voltage organic TFTs, which show highly reliable and reproducible mechanical stability at a bending radius of 5 mm after 1000 cycles. And also, the high radiation stability of the dielectric polymers was observed in a UV-sensitive TFT device, thereby achieving highly reproducible pattern recognition, which is promising for artificial optic nerve circuits.