Flexible small-channel thin-film transistors by electrohydrodynamic lithographyElectronic supplementary information (ESI) available. See DOI: 10.1039/c7nr06075k

• Main Authors: Ding, Yajiang, Zhu, Chen, Liu, Jianpeng, Duan, Yongqing, Yi, Zhengran, Xiao, Jian, Wang, Shuai, Huang, YongAn, Yin, Zhouping
• Format: Article
• Language: English
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c7nr06075k

Small-channel organic thin-film transistors (OTFTs) are an essential component of microelectronic devices. With the advent of flexible electronics, the fabrication of OTFTs still faces numerous hurdles in the realization of highly-functional, devices of commercial value. Herein, a concise and efficient procedure is proposed for the fabrication of flexible, small-channel organic thin-film transistor (OTFT) arrays on large-area substrates that circumvents the use of photolithography. By employing a low-cost and high-resolution mechano-electrospinning technology, large-scale micro/nanofiber-based patterns can be digitally printed on flexible substrates (Si wafer or plastic), which can act as the channel mask of TFT instead of a photolithography reticle. The dimensions of the micro/nanochannel can be manipulated by tuning the processing parameters such as the nozzle-to-substrate distance, applied voltage, and fluid supply. The devices exhibit excellent electrical properties with high mobilities (∼0.62 cm 2 V −1 s −1 ) and high on/off current ratios (∼2.47 × 10 6 ), and they are able to maintain stability upon being bent from 25 mm to 2.75 mm (bending radius) over 120 testing cycles. This electrohydrodynamic lithography-based approach is a digital, programmable, and reliable alternative for easily fabricating flexible, small-channel OTFTs, which can be integrated into flexible and wearable devices. A programmable, photolithography-free and cost-effective procedure for the fabrication of high performance OTFT arrays on ultrathin flexible substrates is reported.