Photon-assisted tunnel rectenna for solar energy harvesting

In this work, we introduce a solar rectenna that is combined with a periodic subwavelength spiral antenna and a metal-oxide-semiconductor photon-assisted tunneling diode. We obtain spectral absorption and electromagnetic field distributions by numerical simulations and calculate the tunneling current densities generated by solar rectenna. The results indicate that broadband absorption with a peak value over 0.99 is achieved in the range of 400-2500 nm. Additionally, the figure of merit for tunneling electric field enhancement reaches over 10⁴. Under AM1.5 solar irradiation, the calculated zero-bias tunneling current densities are up to 13.93 mA/cm². This study is expected to advance the development of ultra-high frequency rectennas and pave the way for efficient solar energy harvesting.