COMPARISON OF TEXTURING METHODS FOR MONOCRYSTALLINE SILICON SOLAR CELLS USING KOH AND Na2C03

We investigate two chemical random texturing methods on mono crystalline silicon wafers. To simulate an industrial process 25 p-type monocrystalline silicon (10x10) cmz wafers are textured in one step. We compare aqueous solutions consisting of potassium hydroxide (KOH) and isopropyl alcohol (IPA) and solutions consisting of sodium carbonate (NazCO3) and sodium hydrogen carbonate (NaHC03). The dependence of the reflectance on etching time, solution temperature and concentration is shown. We achieved weighted reflectance values as low as 12.5% and 16.5% respectively with the two solutions. Furthermore homogeneity and pyramid size are reported. Industrial type solar cells with a homogeneous emitter and screen printed contacts were processed. Efficiencies up to 16.6% with textured surfaces could be achieved for screen printed solar cells on 1 R cm p-type Cz silicon wafers.