Highly doped silicon plasmonic infrared nanoantennas for energy harvesting applications

Abstract

Due to the high need for renewable energy on a worldwide scale, significant research ha s been done on how to use solar energy as a source of free and clean energy. The energy produced is mostly released as electromagnetic radiation with a spectral range of 0.2 to 3 m. New technologies are being developed to harvest this energy while overcoming the limitations of conventional PV devices. These new devices are called nano-antennas (rectenna). Nanoantennas are used to absorb electromagnetic wave radiation especially unused parts of solar radiation (IR region) and the thermal radiation from objects and convert it to electric current and vice versa. Here, a novel design of an "E"-shaped nano-antenna for energy harvesting is introduced and analyzed by using the three-dimensional (3D) finite-difference time-domain (FDTD) method. The key issue in the design of an “E"-shaped nano-antenna for energy harvesting is based on the excitation of surface plasmon polaritons (SPP) through the doped silicon arms of the E shape placed on an Al2O3 substrate to obtain wideband behavior in IR region. In this paper, doped silicon was used instead of noble metal as a plasmonic material with optical resonances in the infrared. The width and length of doped silicon arms are v aried to get the best performance. Doped nanocrystals (NCs) have received more attention lately because through doping the free carrier densities can be changed gradually and active tenability can be achieved.