Thermally-Electrically Tunable Broadband Ultrathin Metal-Free THz Absorber

Thermally-electrically tunable ultrathin metal-free structure of a terahertz (THz) absorber is implemented. The switching capability in absorption response is affirmed by the thermal variations incorporated in the resonators made of phase change material Vanadium-dioxide. The frequency tunability is acquired by the variations in electronic properties of graphene material being utilized as the reflector in the absorber structure. The proposed device offers broadband absorption response of 6.26 THz bandwidth with an ultrathin geometry of thickness of
${\lambda /66.8 } {\mu m};\lambda $
is free space wavelength. Furthermore, the device provides the stable response for a wide angle of incidence of more than 60°.