Silicon nanowire solar cells

Silicon nanowire-based solar cells on metal foil are described. The key benefits of such devices are discussed, followed by optical reflectance, current-voltage, and external quantum efficiency data for a cell design employing a thin amorphous silicon layer deposited on the nanowire array to form the $p\text{-}n$ junction. A promising current density of $\sim 1.6\mathrm{mA}∕{\mathrm{cm}}^2$ for $1.8{\mathrm{cm}}^2$ cells was obtained, and a broad external quantum efficiency was measured with a maximum value of $\sim 12\%$ at $690\mathrm{nm}$ . The optical reflectance of the silicon nanowire solar cells is reduced by one to two orders of magnitude compared to planar cells.