Low-Voltage-Driven Nonvolatile Electrochemical Active Control of Terahertz Transmission in Conductive-Polymer–Nanoresonator Hybrid Devices

Abstract

Active manipulation of terahertz (THz) waves is important for future optoelectronic applications, but most approaches rely on volatile or slow actuation, limiting efficiency and stability. Here, we report a nonvolatile, low-voltage tunable THz transmission device based on electrochemical modulation of a conductive polymer thin film integrated with metallic nanoresonators. A thin film of PEDOT:PSS, deposited via a single-step spin-coating process onto the nanoresonator array, enables efficient modulation of resonance-enhanced THz transmission with a gate voltage of less than 1 V. Our approach achieves reversible and stable switching without any film removal or structural alteration. Resonance-enhanced local fields increase modulation depth to ∼58%, over three times that of the polymer film alone. Furthermore, the electrochemical doping state is retained for a week without continuous power, suggesting memory functionality. Our findings lay the groundwork for the development of next-generation THz metasurfaces, smart modulators, and energy-efficient switching devices.