Fig. 2: Schematics of device structure and high-frequency rectification characteristics.

a Schematic representation of the experimental setup, and the nonequilibrium carrier-diffusion following the DC field-induced symmetry breaking across the channel. b Localized field distribution (middle) near the metal–NiTe₂ interface, as a result of the ac displacement-current oscillation induced by the high-frequency electromagnetic radiation (upper). The optical micrograph of the device is shown at the bottom. c The bias-dependence of the responsivity at different frequencies: 0.04, 0.12, and 0.30 THz. d Electromagnetic power dependence of rectified current at different bias voltages, with the lines being the linear fitting. e Measured resistance (green bars) and rectified currents (red bars: 50 mV bias, blue bars: zero bias) obtained from dozens of devices, highlighting the excellent reproducibility of our experiment. f Device performance recorded after different exposure periods in ambient environment, with the inset showing the corresponding transient time-response. g Room-temperature noise-equivalent power (NEP) at different bias voltage. A satisfactory agreement is found between experimental results (dotted lines) with theoretical predictions (dashed lines).