Associate Professor King Abdullah University of Science and Technology
The increasing energy demands of the world’s population and the quickly diminishing fossil fuel reserves together suggest the urgent need to secure long-lasting alternative and renewable energy resources. Infrared (IR) energy harvesting from waste heat can be a promising contribution for sustainable energy in addition to harvesting from the visible light spectrum. Here, we present a plasmonic rectenna (antenna integrated with a rectifier) for harvesting energy from the Tera hertz (IR) spectrum. The implementation of rectennas for energy harvesting at such high frequencies has remained an elusive research area due to the limitations of nano-scale fabrication and the inability to implement rectifiers that could handle electromagnetic (EM) radiations oscillating at trillion times per second. In this work, a resonant bowtie nano-antenna has been optimized to produce highly enhanced localized fields at the bow tip. The phenomena of plasmon oscillation and hot spot creation at the feed point of the nano-antenna as a result of incident IR energy have been studied through EM simulations and Electron Energy Loss Spectroscopy (EELS). For the rectifier to function at such high frequencies, Metal-Insulator-Metal (MIM) diode has been realized because of its fast response time. The rectenna prototype demonstrates decent zero bias responsivity at a relatively lower dynamic resistance. Optical testing confirms that the device is capable of collecting and rectifying energy at 28.3 THz (10.6 um), albeit with poor efficiency. Numerous challenges in this area and the ways to move forward will also be discussed in this talk.
Associate Professor King Abdullah University of Science and Technology