All-polymer field-effect transistors using a brush gate dielectric

摘要

Interfaces between a poly(3-hexylthiophene) [P3HT] and an end-grafted (brush) layer of poly(methyludmethacrylate) [PMMA] are shown using neutron reflectometry to be dependent on heat treatment.udAnnealing the samples allows part of the brush layer to cross into the P3HT layer creating a veryudasymmetric interface. We suggest that the P3HT rearrangement occurs, creating space for movement ofudthe brush into the film. This interpenetration was observed with two different molecular weight (17.5udand 28 kg mol�1) P3HT films. Output characteristics of devices made from P3HT layers on PMMAudbrushes show that different amounts of heat treatment do not significantly change the deviceudperformance. Saturated hole mobilities are dependent on heat treatment, with devices made from audsmaller molecular weight P3HT (22 kg mol�1) demonstrating larger mobilities than devices createdudusing 48 kg mol�1 P3HT, but only after heat treatment.