A graphene/H-BN van der Waals heterostructure enabling superior (>30 dB) electrical tuning in terahertz devices

Abstract Effective control of terahertz radiation is vital for next-generation wireless communication and sensing. However, achieving efficient tuning of the polarisation, amplitude, and phase of terahertz radiation remains challenging. Here, a device using graphene and hexagonal-Boron Nitride demonstrates superior electrical tuning at Terahertz frequencies. The heterostructure device achieves over 30 dB tuning across a 0.2–1.4 THz range with a practical bias of 24 V, outperforming an equivalent graphene-only device by 20 dB. A highly tunable metamaterial terahertz polarisation converter operating at 0.245 THz is produced using this structure. Benchmark tuning of beam ellipticity (0.73) and rotation angle (42 o ) is achieved at just 15 V, exceeding graphene or complex ionic gel-based devices. This confirms that the heterostructure device tuning can be practically applied to complex devices. The concept of the 2D material heterostructure presented here is adaptable to a plethora of tuneable terahertz devices, opening opportunities for next-generation wireless communications and sensing systems.