화학공학소재연구정보센터
Advanced Functional Materials, Vol.24, No.31, 4959-4968, 2014
Aligned Polythiophene and its Blend Film by Direct-Writing for Anisotropic Charge Transport
A combination of patterning and film alignment techniques helps to build multi-order polymer architecture for application in flexible electronics. A direct-writing method is employed using microcapillary arrays to prepare semiconducting polymer films with both optical and electrical anisotropy. Not only aligned poly(3-butylthiophene) (P3BT) nanowires in neat P3BT films, but also aligned P3BT nanowires within a polystyrene (PS) matrix are obtained, which yields an aligned semiconductor/insulator polymer blend with anisotropic charge transport. The field-effect transistor (FET) mobilities/threshold voltages from both vertical and parallel to alignment directions as well as their dependence on blending ratio are studied. The increased mobility of P3BT/PS blends, as compared with neat P3BT, is observed in both vertical and parallel directions. Using this alignment method, FET mobility and threshold voltage of the semiconductor/insulator polymer blends are comprehensively tuned, from which a digital inverter with gain up to 80 is realized. Therefore, this work not only helps understanding the charge transport mechanism in semiconducting/insulating polymer blends, but also provides an effective approach towards high-performance field-effect transistors with tunable mobility and threshold voltage.