A printed OTFT-backplane for AMOLED display

An AMOLED panel driven by an OTFT-backplane is an attractive display because OTFTs and OLEDs use organic materials with unique characteristics such as low temperature and solution processing ability, and thus are able to implement the key features of future displays. In this study we applied some printing technologies to fabricate an OTFT-backplane for AMOLEDs. Screen printing combined with photolithography with Ag ink was used for the gate electrodes and scan bus lines and contact pads. Ag metal lines with a width of 20 μm and thickness of 60 nm and resistivity of 3.0 × 10−5 Ω cm were achieved. Inkjet printing was applied to deposit TIPS-pentacene as an organic semiconductor. The OTFT-backplane using the Ag gate electrodes and TIPS-pentacene exhibited uniform performance over 17,500 pixels on a 7 in. panel. The mobility was 0.31 ± 0.05 cm2/V s with a deviation of 17%. The AMOLED panel successfully demonstrated its ability to display patterns.

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► An OTFT-backplane was fabricated by using screen printing for gate electrodes and inkjet printing for TIPS-pentacene.
► The average mobility of the OTFTs was 0.3 ± 0.05 cm2/V s with a deviation of 17%, exhibiting uniform performance.
► The backplane was used for an AMOLED panel including 17,500 pixels on a 7 in. panel.