Crosslinkable high dielectric constant polymer dielectrics for low voltage organic field-effect transistor memory devices

In this study, we successfully synthesized water/methanol soluble random copolymers with a high dielectric constant, poly(n-(hydroxymethyl) acrylamide-co-5-(9-(5-(diethylamino)pentyl)-2-(4-vinylphenyl)-9H-fluorene(P(NMA-co-F6NSt)), which contained chemical crosslinkable segment (NMA) and hole trapping building block (F6NSt). The feeding molar ratios of two monomers (NMA:F6NSt) were set as 100:0, 95:5, 80:20, and 67:33 for the copolymers of P1, P2, P3, and P4, respectively. The crosslinked P(NMA-co-F6NSt) thin film could serve as both dielectric and charge storage layers in organic field-effect transistor (OFET) memory device and exhibited high k (i.e., 4.91-6.47) characteristics, leading to a low voltage operation and a small power consumption. Devices based on the P1-P4 dielectrics showed excellent insulating properties and good charge storage performance under a low operating voltage in a range of +/- 5V because of tightly network structures and well-dispersed trapping cites. In particular, P3-based memory device exhibited a large memory window of 4.13 V with stable data retention stability over 10(4) s, a large on/off ratio of 10(4), and good endurance characteristics as high as 200 cycles. The above results suggested that a high-performance OFET memory device could be facilely achieved using the novel crosslinkable high-k copolymers. (c) 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3224-3236