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

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 (≈10⁴) 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.