Broad band absorption silicon nanowire array using diverse radii for photovoltaic applications

In this work, we introduce new silicon nanowire (SiNW) arrays that have broad band absorption spectrum using significantly low material filling ratio. Radii and pitch diversity are employed in designing the proposed SiNW arrays. The arrays are considered 2D infinite in the x and y directions, and composed of vertically aligned cylindrical SiNW that are suspended in air. Computational electromagnetics software Ansys® HFSS is used to compute the absorptance of the array. Results show that diversity of radii in an array plays a significant role in broadening the absorption spectrum, enhancing light trapping, and increasing efficiency. SiNW arrays with continuum radii diversity achieve ~75% efficiency enhancement relative to regular array and 150% relative to equivalent thickness crystalline silicon film.