Photocurable polymer gate dielectrics for cylindrical organic field-effect transistors with high bending stability

Here we describe the use of photocurable poly(vinyl cinnamate) (PVCN) as a gate dielectric in high-performance cylindrical organic field-effect transistors (OFETs) with high bending stability. A smooth-surface metallic fiber (Al wire) was employed as a cylindrical substrate, and polymer dielectrics (PVCN and poly(4-vinyl phenol) (PVP)) were formed via dip-coating. The PVCN and PVP dielectrics deposited on the Al wire and respectively cross-linked via UV irradiation and thermal heating were found to be very smooth and uniform over the entire coated area. Pentacene-based cylindrical OFETs with the polymer dielectrics exhibited high-performance hysteresis-free operation. Devices made with the PVCN dielectric showed superior bending stability than devices made with PVP dielectrics or previously reported cylindrical OFETs due to the good flexibility of the PVCN dielectric. The devices maintained their excellent performance under bending at a bending radius comparable to the lowest value reported for planar OFETs.