UP TO 20 EFFICIENT SOLAR CELLS ON MONOCRYSTALLINE SILICON WAFERS BY USING A KOH – HIGH BOILING ALCOHOL (HBA) TEXTURING SOLUTION

摘要

We have textured (100) p-type Czochralski (Cz) monocrystalline Silicon (Si) wafers by using anaqueous solution of potassium hydroxide (KOH) and a High Boiling Alcohol (HBA). Cz-Si wafers textured with theKOH-HBA solution were processed into solar cells via the standard industrial screen printing method and anadvanced industrial process (selective emitter process). Also, high quality float zone (FZ) Si material was texturedand processed into solar cells by using a lab-type cell process. Industrially processed cells achieve efficiencies of17.6% and 18.2%, respectively. Lab-type processed cells (2×2 cm~2) achieve an efficiency of up to 20%. In addition,for the standard KOH-Isopropyl alcohol (IPA) etching solution a new etching bath setup has been developed. Thenew bath setup allows the recuperation of IPA during the texturisation process, as well as vacuum processing stepsduring the texturisation, which considerably reduces etching time.