Highly Efficient Solid Gear-Shaped Silicon Nanowire for Solar Energy Harvesting

Silicon nano-wire (SiNW) is a viable solution to harvest large amount of photons from the sun. In this letter, novel solid gear-shaped SiNW is presented and particle swarm optimization technique is used to optimize its geometrical parameters. The defined optimization goal was to increase the absorption capabilities of the proposed SiNW at the maximum wavelength emission of the sun,
$\lambda =500$
nm. For the sake of fabrication flexibility, we have also introduced the complementary of the proposed optimized SiNW with the same optimized dimensions. The optimal SiNW and its complementary structure with 1-
$\mu \text{m}$
-thick Si substrate offer ultimate efficiencies of about 50.21% and 45.12% employing 3-D-finite-difference time-domain method. It is worth noting that the ultimate efficiencies of the proposed SiNWs are higher than that of the previous work of slanting SiNWs and funnel-shaped SiNW.