Fully Drawn All‐Organic Flexible Transistors Prepared by Capillary Pen Printing on Flexible Planar and Curvilinear Substrates

Abstract

Printing technologies are instrumental to the fabrication of low‐cost lightweight flexible electronic devices and circuits, which are necessary to produce wearable electronic applications. However, attaining fully printed devices on flexible films over large areas has typically been a challenge. Here, the fabrication of fully drawn all‐organic field‐effect transistor (FET) arrays on mechanically flexible substrates using a capillary‐pen printing method is demonstrated. A highly crystalline organic semiconductor (active layer), a smooth insulating polymer (dielectric layer), and a conducting polymer (source, drain, and gate electrodes) are deposited from solution sequentially. The bottom‐gate bottom‐contact FETs drawn onto flexible substrates exhibit superior field‐effect mobilities of up to 0.54 cm2 V−1 s−1, good reproducibility, operational stability, and mechanical bendability. Furthermore, to emphasize the methodological advantages of the capillary‐pen printing, an organic FET (OFET) array on a curvilinear substrate of a plastic straw and the repairing concept for a broken electrical circuit are demonstrated. These results indicate that capillary pen printing shows promise as a manufacturing technique for a wide range of large‐area electronic applications.

Recent Process of Flexible Transistor‐Structured Memory

“…Traditional inorganic substrates are rigid and brittle, so they are not directly applicable to flexible devices. Polymer materials such as polyethylene terephthalate (PET), [19][20][21] polyethylene-2, 6-naphthalate (PEN), [22][23][24] and polydimethyl siloxane (PDMS) [25][26][27] are used widely due to their chemical stability, ideal mechanical and physical properties. The mechanical flexibility test in earlier studies mainly included repeated inward or outward bending with strains S induced on the surface of substrate (Figure 2a,b).…”

Emerging Considerations for the Future Development of Electrochemical Paper‐Based Analytical Devices

“…The inks limit the screen‐printing technique because their formulation uses organic solvents that are susceptible to temperature and humidity, which vary the standardized concentrations and viscosity. Furthermore, the technique presents low resolution, high ink waste, and imprecision due to the low contact pressure during fabrication ,…”

Heterogeneous Monolithic Integration of Single‐Crystal Organic Materials

“…The average field‐effect mobility, threshold voltage, and on/off current ratio were 0.025 cm 2 V −1 s −1 , 3 V, and 10 5 , respectively. Moreover, it was demonstrated that an array of all‐organic flexible FETs could be drawn on flexible substrates using only the capillary‐pen printing method ( Figure ) . OFETs with a bottom‐gate/bottom‐contact configuration were fabricated as follows (Figure b).…”

“…Photographs showing each stage of a sequential capillary‐pen printing process for fabrication of a TIPS‐PEN OFET array (bottom). Reproduced with permission . Copyright 2015, John Wiley & Sons.…”