A simple lithography-free approach for the fabrication of top-contact OFETs with sub-micrometer channel length

Here, we show the fabrication of sub-micrometer channel devices that are patterned by a simple inclined thermal evaporation approach. This structuring methodology with the capability to produce electrodes with distances even below 100 nm is compatible with solution-based fabrication methods commonly applied to deposit high-mobility organic semiconductor films or even high-capacitance polymer gate dielectrics. As the contacts are directly defined through thermal evaporation without the need for any expensive masks or lithography techniques, it offers the possibility of simple, lab-scale assessment of promising material combinations in the development of high-performance organic transistors through direct access to sub-micrometer channel device characteristics. Here, we focus on the structuring method, show example devices with sub-micrometer channel lengths, and discuss the potential applications of this methodology as a lab-scale test vehicle for OFET development.