Development of high-performance n-type organic thin-film transistors using a small-molecule polymer blend

We report the fabrication of high-performance solution-processed organic field-effect transistors (OFETs) using small-molecule polymer blends as the active layer. N,N-dialkyl-substituted-(1,7&1,6)-dicyanoperylene-3,4:9,10-bis (dicarboximide) derivative (PDI-RCN2) and polystyrene (PS) or poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(benzo[2,1,3]thiadiazol-4,8-diyl)] (F8BT) are used as the small molecules and polymer binders, respectively, that comprise the semiconducting layer. Both the n-type PDI-RCN2 and PS or F8BT-blended OFETs have high field-effect mobility (μFET) of 0.4 cm2/Vs, with average μFET values of 0.25 and 0.16 cm2/Vs for PDI-RCN2/F8BT and PDI-RCN2/PS, respectively. Moreover, OFETs with blended active layers exhibit significantly improved device-to-device uniformity and reproducibility, as evidenced by the μFET standard deviations of 0.23, 0.1, and 0.12 for PDI-RCN2, PDI-RCN2/PS, and PDI-RCN2/F8BT, respectively.