Large area macroporous silicon layers for monocrystalline thin-film solar cells

Abstract

We produce uniform macroporous double-layers on 6 inch n-type silicon substrates by electrochemical etching under rear side illumination in a hydrofluoric acid (HF)-based electrolyte. The etched area is circular with a diameter of 13 cm. We demonstrate the detachment of 20 μm thick free-standing macroporous silicon layers with an area of 8 × 8 cm ² .