@article{article_769726, title={A Terahertz Metamaterial Absorber-Based Temperature Sensor Having Nine Resonance Peaks}, journal={Gazi University Journal of Science}, volume={34}, pages={1163–1177}, year={2021}, DOI={10.35378/gujs.769726}, author={Bağcı, Fulya}, keywords={Tunable metamaterial, Polarization-insensitive, Absorption ratio, Terahertz frequency, Temperature sensing}, abstract={<div style="text-align:justify;">Design and investigation of a polarization-insensitive nine-band tunable metamaterial absorber at THz frequencies with equal to or more than 90% absorption ratio in all of the bands are reported. The tunable metamaterial absorber consists of four isosceles triangle patches with four U-shaped cut paths on top of an indium antimonide substrate, which has a fully metallic ground plane at the backside. Numerical analyses show that the metamaterial absorber has wide-angle characteristics under transverse-electric and transverse-magnetic modes. The permittivity of indium antimonide is highly dependent on temperature variations due to its temperature-dependent intrinsic carrier density, leading to shift of nine absorption peak frequencies upon change of environment temperature. Broadband switching of nine absorption peak frequencies with maximum 71.5% shift ratio between 190 K and 230 K is obtained. Temperature sensing performance of the metamaterial absorber is further evaluated and the sensitivities are found to be 11.5 GHz/K, 9.2 GHz/K, 8.3 GHz/K, 7.6 GHz/K, 7.0 GHz/K, 6.2 GHz/K, 5.3 GHz/K, 4.5 GHz/K and 4.2 GHz/K, from the first to ninth absorption band, respectively. Therefore, the proposed nine-band metamaterial absorber sensor has great potential in sensitive and accurate temperature measurement, absorption tuning in optoelectronic applications and as frequency selective thermal emitters. </div>}, number={4}, publisher={Gazi University}, organization={Türkiye Bilimsel ve Teknolojik Araştırma Kurumu (TÜBİTAK), Ankara University}