Direct laser patterning of organic semiconductors for high performance OFET-based gas sensors

Abstract

Effective patterning of organic semiconductor (OSC) films is an essential prerequisite for large-scale fabrication of organic functional electronics. Although photolithography is a reliable patterning method and is a mature technique, the preparation of microstructured OSC layers with photolithography has been suffering from a sophisticated fabrication procedure. Herein, we demonstrate a robust femtosecond (fs) laser assisted patterning method, which can be effectively used to fabricate microstructured OSC thin films through direct layer ablation of organic materials. Using a well optimized manufacturing procedure, the ablation of both polymeric materials and small molecules is well modulated, and the resulting OSC thin films display typical pore patterns with a feature size less than 2 μm and nearly unaffected charge transport properties. Organic field-effect transistors (OFETs) fabricated on the microstructured OSCs show enhanced gas sensing behavior, with a responsivity to gaseous ammonia ranging from 0.5 to 10 ppm. This work shows that direct laser patterning of organic semiconductors is an effective approach for microstructure fabrication, and highlights the potential application of this method in future organic electronics.