We report a large-area, simple wire-bar?coating process as a suitable method for deposition of conjugated and insulating polymer films in OFET arrays and complementary ICs. The highly crystalline polymer semiconductor, PTVPhI-Eh, showed better crystalline morphology and the amorphous polymer semiconductor, (MEH-PPV) or PMMA, exhibited smoother film morphology when applied via the bar-coating process than by the spin-coating process. The best bar-coated OFETs with DPPT-TT showed a charge carrier mobility as high as 2.83 cm2 V-1 s-1 and excellent device-to-device performance uniformity with standard deviation of 0.05~0.06 in 4 inch transistor arrays. Finally, we fabricated bar-coated ambipolar CMOS inverters (voltage gain ＞40) and ring oscillators (ROs) (oscillation frequency (fosc) of ~25 KHz) with a PTVPhI-Eh and CsF interlayer. We believe that this simple printing method is not only very effective for producing high performance device and circuits, but also highly compatible with roll-to-roll continuous manufacturing processes, which will enable fully printed large-area electronic and optoelectronic devices.
Figure. 1 (a) Top-surface AFM images of the PTVPhI-Eh semiconductor thin fi lms deposited using (a) spin-coating and (b) bar-coating methods. (c) Schematic description of the bar-coating process. (d) Digital camera images of the bar-coated PTVPhI-Eh OFET array on a large size (10 cm × 10 cm)