Large-Area Uniform Polymer Transistor Arrays on Flexible Substrates: Towards High-Throughput Sensor Fabrication

Solution-processable organic semiconductors can serve as the basis for new products including rollable displays, tattoo-like smart bandages for real-time health monitoring, and conformable electronics integrated into clothing or even implanted in the human body. For such exciting commercial applications to become a reality, good device performance and uniformity over large areas are necessary. The design of new materials has progressed at an astonishing pace, but accessing their intrinsic, efficient electrical properties in large-area flexible device arrays is difficult. The development of protocols that allow integration with industrial-scale processing for high-throughput manufacturing, without the need to compromise on performance, is the key for transitioning these materials to real-life applications. In this work, large-area arrays of organic thin-film transistors obtained by spray-coating the high-mobility polymer indacenodithiophene-co-benzothiadiazole (IDTBT) are demonstrated. A maximum charge carrier mobility of 2.3 cm² V⁻¹ s⁻¹, with a very narrow performance distribution, is obtained over surface areas of 10 cm × 10 cm. The devices retain their electrical properties when bent multiple times and at different curvatures. In addition, large arrays of highly sensitive (0.25% change in mobility for 1% humidity variation), reusable, near-identical humidity sensors are produced in a one-step fabrication and calibrated from 0% to 94% relative humidity.