High Performance Flexible Transistors With Polyelectrolyte/Polymer Bilayer Dielectric

Flexible organic field-effect transistors (OFETs) consisting of polyvinyl alcohol (PVA)/ polyelectrolyte polyacrylic acid (PAA) bilayer gate dielectric are demonstrated. These devices exhibited maximum field-effect mobility of \mu _{\text {max}} ~\sim {0.94} cm ^{{2}}\cdot \text{V}^{-{1}}\cdot \text{s}^{-{1}} with an average of \mu _{\text {avg}} ~\sim {0.7} (±0.1) cm ^{{2}}\cdot \text{V}^{-{1}}\cdot \text{s}^{-{1}} in the saturation regime and {I}_{ \mathrm{\scriptscriptstyle ON}}/{I}_{ \mathrm{\scriptscriptstyle OFF}} of \sim 10^{{4}} with an operating voltage of −5 V. Apart from high electrical stability upon bias stress and repeated measurement of transfer curves, these devices showed excellent stability in electrical performance upon being subjected to sequential bending in various directions, i.e., vertical, horizontal, and diagonal to the channel length. Even after the application of 500 cycles of bending, no significant degradation in {I}_{ \mathrm{\scriptscriptstyle ON}} was observed. This very high electromechanical stability in devices was achieved due to a super strong and highly tough hydrogen-bonded polyelectrolyte/polymer bilayer dielectric. In addition, external resistor-loaded inverters were also demonstrated with these devices to evaluate the circuit performance.