Organic Thin-Film Transistor Using High-Resolution Screen-Printed Electrodes

Abstract

Organic thin-film transistors and inverters were fabricated with screen-printed electrodes. The screen printing ink was formulated with silver nanoparticles for high conductivity and carbon black for a high work function. Under optimum fabrication conditions, a pattern as small as 30 mm could be fabricated. The field effect mobility was calculated to be 7 Â 10 À2 cm 2 V À1 s À1 from the organic thin-film transistor. For this transistor, the ratio of silver nanoparticles to carbon black for screen-printed electrodes was 30 to 70 wt %.

Screen Printing of Highly Loaded Silver Inks on Plastic Substrates Using Silicon Stencils

“…Screen printing has been widely employed to produce silver electrodes for applications such as transistors, sensors, solar cells, and touch screens. − This printing method uses a screen mask, typically consisting of a woven mesh, and a patterned stencil attached to the mesh. Ink pressed on the screen mask by a squeegee passes through the portions of the mesh that are not covered by the stencil material.…”

Recent Advances in Organic Transistor Printing Processes

“…Rogers et al described screen-printed OFETs in combination with micromolded carbon paint for the preparation of S/D electrodes . More recently, OFETs with a channel length of 30 μm were fabricated by Lim et al (Figure c) . Screen-printed metal electrodes were prepared from a solution containing Ag nanoparticles mixed with carbon black to achieve a high conductivity and work function.…”

“…(c) Ag nanoparticle/carbon black electrodes fabricated using conventional screen-printing equipment. Reproduced with permission from ref . Copyright 2009 The Japan Society of Applied Physics.…”

Experimental Techniques for the Fabrication and Characterization of Organic Thin Films for Field-Effect Transistors

“…An obvious disadvantage of this technique is the relatively low resolution (∼75 μm), especially for forming the critical dimensions in transistors. However, recent improvements have indicated that features as small as 30 μm can be achieved . OTFTs and inverters were fabricated using screen-printed electrodes.…”