All jet-printed polymer thin-film transistor active-matrix backplanes

Abstract

Thin-film transistor (TFT) backplanes fabricated by using jet printing as the only patterning method are reported. Additive and subtractive printing processes are combined to make 128×128 pixel active matrix arrays with 340μm pixel size. The semiconductor used, a regioregular polythiophene, poly[5,5′-bis(3-dodecyl-2-thienyl)-2,2′-bithiophene]; (PQT-12) is deposited by inkjet printing and exhibits average TFT mobility of 0.06cm2∕Vs, on/off ratios of 106, and minimal bias stress. The printed TFTs have high yield with a narrow performance distribution. The pixel design benefits from the registration accuracy of jet printing and it is shown that the electrical performance is suitable for addressing capacitive media displays.

Ambient Electronics

“…Various prototype integrated circuits with organic transistors have been fabricated by printing technologies such as inkjet printing, 27,[46][47][48] microcontact printing, [49][50][51] nanoimprinting, 52,53) offset printing, 54) and screen printing. 48) In 2004, Ana Arias of Palo Alto Research Center, Xerox, and colleagues fabricated 128 Â 128 cell organic transistor matrix arrays with a resolution of 75 dpi (340 m pixel size) by inkjet printing.…”

“…By using the spin-coated polymer semiconductor, polyquater-thiophene (PQT-12), for the organic semiconductor layers, a mobility of 0.1 cm 2 V À1 s À1 was achieved. 47) In 1993, George Whitesides of Harvard University and colleagues developed a patterning technique for stamping ultrafine metal thin films formed on a silicon wafer to various substrates; this technique is known as soft lithography. 49) More recently, John Rogers and colleagues succeeded in stamping inorganic semiconductors and thinfilm electrodes to various substrates by applying this transfer technique, and fabricated not only flexible devices but also stretchable electronic devices.…”

Ultraflexible organic electronics

“…Organic thin-fi lm devices are expected to yield simultaneously large-area, lowcost, lightweight, and fl exible devices because they can easily be fabricated on polymer fi lms by printing processes such as inkjet printing. [44][45][46][47][48] In this article, we review recent progress on large-area, ultrafl exible, and stretchable organic electronics and related technologies. In particular, ultrafl exible organic thin-fi lm devices such as organic thin-fi lm transistors (OTFTs), [49][50][51][52][53] organic photovoltaic (OPV) cells, 54 and organic light-emitting diodes (OLEDs) 55,56 are described.…”

Inkjet-printed graphene electronics

“…11,18 So far SWNT ink-jet printed devices measured at room conditions have µ no larger than ∼1cm 2 V −1 s −1 (at ON/OFF ratio∼10), 29 which is two orders of magnitude smaller than our graphene ink-jet printed TFTs. Organic semiconducting inks [131][132][133] suffer from low µ, limited by variable range hopping of charges between the isolated polymer chains. 137 The overall charge conduction in crystalline organic semiconducting thin films is determined by both intra-chain and inter-chain charge transport.…”

“…140 Embedding SWNTs in the semiconducting ink allowed us to get µ ∼ 0.07cm 2 V −1 s −1 at room conditions. 27,28 Page 23 of 40 22 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 We combine our graphene-ink with one of the most common organic polymer in ink-jet printing, Poly[5,5'-bis(3-dodecyl-2-thienyl)-2,2'-bithiophene] (PQT-12) [131][132][133] in order to investigate its viability as interchain hopping enhancer. PQT-12 is widely used due to the higher environmental stability (up to 300 days at room conditions 141 ), with respect to other organic semiconducting inks.…”