High-Performance Zero-Bezel Thin Film Transistor Backplane Using Foldable Substrates

Abstract

These days, there is a growing need for flexible and foldable electronics. Especially, foldable electronics has been the terminal goal of flexible or bendable electronic devices, and is still in the beginning stage of research unlike flexible devices. In this study, we present unconventional fabrication methods of TFT arrays on pre-designed damage-free foldable substrates. Also, we demonstrate how these devices can be folded into various arbitrary shapes. Completely foldable electronics require elastic substrates with stable device components that can withstand tensile or compressive forces by mechanical folding. Instead of papers, plastics or elastomeric films, we formed foldable substrates composed of rigid and foldable elastic areas with designed patterns. These two parts allow the substrate to be deformed freely into pre-memorized structures without any damage. We fabricated foldable TFT arrays as TFT backplanes for displays using these foldable substrates and foldable interconnects. This device show outstanding properties with high mobilities (~6 cm2/V•s) and strong reliability. These results represent substantial progress towards flexible and wearable electronics through the folding capability.