Recent Advances in Tunable/Reconfigurable Terahertz Metadevices Based on Phase-Change Materials

Emerging artificial intelligence and Internet of Things (IoT) technologies have greatly enhanced daily life, yet processing vast data volumes poses challenges for computing hardware and communication systems. Terahertz (THz) waves, positioned between microwaves and infrared light, offer significant potential for future communication and sensing applications due to their wide bandwidth, high data rate, superior resolution, and non-destructive capabilities. However, traditional passive THz devices face adaptive control and dynamic modulation limitations. The emergence of tunable and reconfigurable metadevices, especially those using phase-change materials, provides promising solutions through substantial and rapid modulation of electromagnetic responses. This review examines recent advancements in THz metadevices utilizing phase-transition materials, focusing on mechanisms like insulator-to-metal transitions, amorphous-to-crystal transformations, ferroelectric behavior, and liquid-crystal transitions. It summarizes strategies in structural design, material selection, and device fabrication. Furthermore, it discusses the latest developments in THz modulation and applications using phase-change metadevices, highlighting key performance parameters such as frequency range, modulation depth, tunability, and switching speed. Finally, the review outlines current challenges and future prospects in advancing adaptive THz metadevices, pointing to potential pathways for dynamic, multifunctional THz systems.