Enhanced Thin Solar Cells Using Optical Nano-Antenna Induced Hybrid Plasmonic Travelling-Wave

A new method is proposed to trap the light inside the solar cells. In this method, a nanoantenna structure with hybrid plasmonic travelling wave is designed and implemented in the silicon-based solar cell, to redirect the incident light. The antenna converts the vertically propagating light to a guiding mode travelling in the lateral direction of the solar cell resulting in enhanced absorption. The Floquet's theorem in conjunction with surface plasmon theory is used to design the antenna; and a three-dimensional full-wave numerical analysis is done to validate the design. The antenna is implemented in the solar cell structure, and the characteristics of proposed structure are numerically analyzed using finite-difference frequency domain method. Simulation results show that by using the proposed nanoantenna as the back contact of the solar cell, absorbance is significantly enhanced in visible and infrared range of solar spectrum and the short circuit current of the solar cell is enhanced for both TM and TE polarization by a factor of 1.32 and 1.30, respectively.