Vivaldi dipole nano‐rectenna for IR energy harvesting at 28.3 THz

Abstract

AbstractA Vivaldi dipole rectenna system for infrared (IR) energy harvesting is investigated. First, a parametric study on the Vivaldi dipole antenna is performed to collect the maximum electric field between the Vivaldi poles. The antenna arms were optimized to achieve a high‐efficiency rectenna system. The two arms of the antenna were formed using two different metals, that is, gold and titanium. These two metals have different work functions, which facilitate the diode operation through tunneling at zero bias. The two arms of the Vivaldi dipole are overlapped, and a suitable insulator layer is injected in the overlapped area to form the metal‐insulator‐metal (MIM) diode. The MIM diode is an ideal candidate for this operation as it works without any bias, provided the two metals have different work functions. For rectenna operation, it is crucial that the rectifying diodes should work without any aid of external bias. The Al2O3 is the insulator layer of the MIM diode. We have chosen Al2O3 because it has a low dielectric constant at terahertz frequency regime, which allows us to match the operational cut‐off frequency, that is, 28.3 THz. A parametric study of the Al2O3 insulator layer is performed to increase the captured received intensity. At the end, the nano‐antenna operates at a frequency band of [26 … 30 THz] to harvest IR energy from the environment with good efficiency and demonstrate its capacity to capture incident waves and obtain high‐intensity values within its gap. It is a development that could eventually boost electricity generation.