Tunnel Thin‐Film Transistors for Ultralow‐Power and High‐Performance Flexible Electronics

Abstract Thin‐film transistors (TFTs) are the cornerstone of large‐area electronics, yet their capacity to enable low‐power flexible technologies has been stifled by a fundamental constraint: the thermionic limit, which restricts the subthreshold swing (SS) to ≈60 mV dec −1 at room temperature. This intrinsic barrier has persisted as a critical bottleneck, impeding advancements in applications from wearable sensors to low‐power flexible electronics. Here, flexible tunnel TFTs that harness quantum band‐to‐band tunneling are reported to transcend this fundamental limit. This tunnel TFTs, fabricated on an ultrathin (6 µm) flexible substrate, deliver subthermionic SS (28.8 mV dec −1 ) with a large intrinsic gain (≈10 4 ) under a mere 1 V operating voltage. By using a protective layer‐assisted photolithography method, flexible tunnel TFT active‐matrix arrays, flexible amplifiers, and various flexible logic circuits are successfully fabricated. The flexible tunnel TFT array can be bent multiple times with negligible degradation to a radius as small as 50 µm. The flexible amplifier shows a high gain of 1000 V/V, enabling the acquisition of high‐quality electromyography signals with a signal‐to‐noise ratio of 77 dB. All the logic circuits demonstrate accurate Boolean output functionalities at picowatt‐level power consumption, opening a new device concept for energy‐efficient flexible electronics.