Fast patterning of oriented organic microstripes for field-effect ammonia gas sensors
Binghao Wang1, Jinqiang Ding2, Tao Zhu2
1Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123, China. lzhuang@suda.edu.cn chilf@suda.edu.cn and Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA.
Abstract:
A series of organic field-effect transistors (OFETs) with patterned ultra-thin films for NH3 detection are achieved via fast dip-coating. The morphology and packing structure of the ultra-thin films are greatly dependent on the surface energy of the substrates, geometry features of the patterned electrodes and evaporation atmosphere during the dip-coating process, which in turn results in a significant difference in the NH3 sensing properties. Based on the newly proposed mechanism, low-trap dielectric-semiconductor interfaces, a stripe-like morphology and an ultrathin film (as low as 2 nm) enable the OFET-based sensors to exhibit unprecedented sensitivity (∼160) with a short response/recovery time. The efficient (2 mm s(-1)), reliable, and scalable patterning strategy opens a new route for solution-processed OFET-based gas sensors.
