Texturing of polycrystalline silicon [solar cells]

A simple texturing procedure suitable for polycrystalline solar cells is described that matches the performance of anisotropic etching on single crystal wafers. Single crystal wafers are typically etched with anisotropic etches relying on knowledge of crystal orientation not possible with the random grain orientation in polycrystalline silicon. Solar cells are encapsulated before field deployment and with suitable surface texturing, total internal reflection from the air/glass interface is used to minimize reflection losses. A wet chemical isotropic etch is used to produce surface texturing, with moderate to large inclination relative to the original wafer surface. Reflection measurements from encapsulated samples show reflection losses after the isotropic etch are comparable with those from inverted pyramids or microgrooves. The isotropic etch has superior light trapping properties, important in thin cells produced by epitaxy and other techniques