Optimized light absorption in Si wire array solar cells

Abstract

Reducing reflection and transmission losses in photovoltaic devices is essential for realizing highly efficient power conversion. Here, we theoretically investigate arrays of radial junction silicon wires to determine the optimal geometry for maximized light absorption. Using a generalized rigorous coupled wave analysis, we calculate the scattering spectra of arrays of varying wire radii, length, and lattice filling factors. Near unity absorption, far exceeding that of conventional thin film devices, is calculated for a square array of 20  µm long wires with radii of 200 nm and a filling fraction of 30%. These results suggest a potentially cost-effective route toward high efficiency solar cells.