Anti-Reflective Porous Silicon Features by Substrate Conformal Imprint Lithography for Silicon Photovoltaic Applications

Silicon photovoltaic cells require anti-reflection treatments in order to minimise optical losses and improve cell efficiencies. Commercially, the silicon surface is textured using a chemical etchant followed by the addition of an anti-reflective coating to further suppress reflectivity. We present a process using metal assisted etching to create porous silicon features capable of reducing reflectivity to less than 5%. A method for producing porous silicon using Substrate Conformal Imprint Lithography (SCIL) has been developed in order to pattern the nanoscale anti-reflective structures onto silicon wafers.