AQUEOUS ACIDIC ETCHING SOLUTION AND METHOD FOR TEXTURING THE SURFACE OF SINGLE CRYSTAL AND POLYCRYSTAL SILICON SUBSTRATES

摘要

AN AQUEOUS ACIDIC ETCHING SOLUTION SUITABLE FOR TEXTURING THE SURFACE OF SINGLE CRYSTAL AND POLYCRYSTAL SILICON SUBSTRATES AND CONTAINING, BASED ON THE COMPLETE WEIGHT OF THE SOLUTION, - 3 TO 10% BY WEIGHT OF HYDROFLUORIC ACID; - 10 TO 35% BY WEIGHT OF NITRIC ACID; - 5 TO 40% BY WEIGHT OF SULFURIC ACID; AND - 55 TO 82% BY WEIGHT OF WATER; A METHOD FOR TEXTURING THE SURFACE OF SINGLE CRYSTAL AND POLYCRYSTAL SILICON SUBSTRATES COMPRISING THE STEP OF (1) CONTACTING AT LEAST ONE MAJOR SURFACE OF A SUBSTRATE WITH THE SAID AQUEOUS ACIDIC ETCHING SOLUTION; (2) ETCHING THE AT LEAST ONE MAJOR SURFACE OF THE SUBSTRATE FOR A TIME AND AT A TEMPERATURE SUFFICIENT TO OBTAIN A SURFACE TEXTURE CONSISTING OF RECESSES AND PROTRUSIONS; AND (3) REMOVING THE AT LEAST ONE MAJOR SURFACE OF THE SUBSTRATE FROM THE CONTACT WITH THE AQUEOUS ACIDIC ETCHING SOLUTION; AND A METHOD FOR MANUFACTURING PHOTOVOLTAIC CELLS AND SOLAR CELLS USING THE SAID SOLUTION AND THE SAID TEXTURING METHOD.