Bilayer Metal Oxide Channel Thin Film Transistor with Flat Interface Based on Smooth Transparent Nanopaper Substrate

With the rapid development of electronic devices, a lot of electronic waste is generated yearly. They posed sereve environmental concerns. Integrating sustainable materials into electronic devices is one of promising solutions to achieve the balance between technological development and ecological protection. Cellulose nanopaper has emerged as a hot sustainable material for thin film transistors (TFT) in the flexible display. However, the performance of nanopaper TFT is generally poor. In this study, a transparent nanopaper with a root-mean-square surface roughness of 3.49 nm is prepared by spin coating cellulose nanofibrils on glass and applied as a substrate for metal oxide TFTs. Bilayer channel (IGZO/Al $_{{2}}\text{O}_{{3}}$ ) TFTs with bottom gate structure are then deposited on transparent nanopaper by physical vapor deposition at room temperature. Consequently, the as-prepared nanopaper TFT not only exhibits a saturation mobility of as high as 21.98 cm2/(V·s), an $\text{I}_{\text {on}}/\text{I}_{\text {off}}$ ratio of ${5.07}\times {10} ^{{6}}$ , and a subthreshold swing of 0.75 V/dec, but shows good bias stability. This work brings a step closer to green, sustainable, and inexpensive transparent paper electronics.