All-additive ink-jet-printed display backplanes: materials development and integration
In this report methods used to deposit and integrate solution processed materials to fabricate TFT backplanes by inkjet printing are discussed. The materials studied allow the development of an all additive process in which materials are deposited only where their functionality is needed. The metal layer and semiconductor are printed and the solution processed dielectric is spin coated. Silver nanoparticles are used as gate and data metals, the semiconductor used is a polythiophene derivative (PQT-12) and the gate dielectric is an epoxy-based photopolymer. The maximum processing temperature used is 150 „aC making the process compatible with flexible substrates. The ION/IOFF ratio was found to be around 105-106 and TFT mobilities of 0.01 cm2/Vs were obtained. The influence of surface treatments on the size and shape of printed features is presented. It is shown that coffee stain effects can be controlled with ink formulation and that devices show the expected pixel response.
Arias, A. C.; Daniel, J.; Krusor, B.; Ready, S.; Sholin, V.; Street, R. A. All-additive ink-jet-printed display backplanes: materials development and integration. Journal of the Society for Information Display. 2007 July; 5 (7): 485-490.