Inorganic Dual-Gate ZnO–Te Anti-Ambipolar Switches for Electrically Programmable Window Detection and Multi-Level Voltage Classification

The anti-ambipolar switch (AAS) produces a bell-shaped (Λ) transfer characteristic that embeds two threshold edges within a single device; however, this feature has been utilized mainly for discrete logic and periodic signals, rather than for discriminating a continuous input against defined voltage thresholds. Herein, a dual-gate ZnO–Te AAS (DGAAS), combined with a load transistor into an AAS cell, functions as an electrically programmable window detector. The bounded conduction interval of its Λ-curve defines the detection window, and the top-gate bias relocates this window without changes to the circuit topology. Fabricated at ≤150 °C, the device translates its peak by 0.95 V per volt of top-gate bias, with a device-to-device standard deviation of 29.4 mV across 30 devices. A six-transistor window detector, comprising the AAS cell and an output buffer, replaces the two-comparator-and-AND structure of a conventional CMOS design, reducing the transistor count by 75–77%, and circuit simulations based on the measured cell characteristics show that three cells map a continuous analog input to a 2-bit digital output. These results indicate that the ZnO–Te DGAAS serves as a compact primitive for voltage-domain signal discrimination, connecting analog sensing and digital readout within a back-end-of-line (BEOL)-compatible process.