In/Nb₂O₅ interfaces designed as enhanced broadband light absorbers, terahertz optical filters and quad band antennas

Herein, thin films of Nb2O5 are deposited onto semitransparent indium and glass substrates using the sputtering technique. Optical analyses revealed significant improvement in light absorption, displaying a maximum enhancement of 1900% at an incident photon energy of 2.29 eV. The dielectric constant of Nb₂O₅ is increased by 289% after coating onto indium substrates. In addition it increased the values of terahertz cutoff frequency making the In/Nb₂O₅ interfaces promising for use as optical band filters adequate for terahertz technology. On the other hand the experimentally designed In/Nb₂O₅/Ag antennas were tested in the frequency domain of 0.01–1.80 GHz. The antennas exhibited excellent performance across the quad-band range. The four lower bandstop edges of the AC transmission line are centered at 0.67 GHz, 1.19 GHz, 1.42 GHz, and 1.65 GHz. Additionally, the MIM antenna demonstrated a negative capacitance effect beneficial for canceling passive antenna modes, thereby resulting in high transmission rates with minimal power loss.