In this study, a novel process using ink jet printing with dilute PMMA [poly(methylmethacrylate)] solution to form fine separation banks as confined boundaries for the subsequent depositing poly(3,4–ethylene dioxythiophene) (PEDOT) was proposed. The PEDOT comprised the source and drained electrodes with a gap of several micrometers due to the innate characteristic of the ring edge of ink jetted PMMA. Using this technique, the organic device was designed with a bottom gate and evaporated pentacene as the channel material. The device mobility and on/off ratio were about 3.6×10-4 and 2×102/V sec, respectively.
Jhih-Ping Lu, Ying-pin Chen, Yuh-Zheng Lee, Kevin Cheng, Fang-Chung Chen, "Ring Edge in Film Morphology: Benefit or Obstacle for Ink Jet Fabrication of Organic Thin Film Transistors" in Journal of Imaging Science and Technology, 2007, pp 461 - 464, https://doi.org/10.2352/J.ImagingSci.Technol.(2007)51:5(461)