Title :
Comparison of texturing methods for monocrystalline silicon solar cells using KOH and Na/sub 2/CO/sub 3/
Author :
Sparber, W. ; Schultz, O. ; Biro, Daniel ; Emanuel, G. ; Preu, R. ; Poddey, A. ; Borchert, D.
Author_Institution :
Fraunhofer-Inst. fur Solare Energiesysteme, Freiburg, Germany
Abstract :
We investigate two chemical random texturing methods on mono crystalline silicon wafers. To simulate an industrial process 25 p-type monocrystalline silicon (10/spl times/10) cm/sup 2/ 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 (Na/sub 2/CO/sub 3/) and sodium hydrogen carbonate (NaHCO/sub 3/). 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 /spl Omega/cm p-type Cz silicon wafers.
Keywords :
elemental semiconductors; etching; reflectivity; silicon; solar cells; surface texture; Si; aqueous solutions; chemical random texturing method; etching time; homogeneous emitter; industrial process; industrial type solar cells; isopropyl alcohol; monocrystalline silicon solar cells; monocrystalline silicon wafers; potassium hydroxide; screen printed contacts; screen printed solar cells; sodium carbonate; sodium hydrogen carbonate; textured surfaces; weighted reflectance values;
Conference_Titel :
Photovoltaic Energy Conversion, 2003. Proceedings of 3rd World Conference on
Print_ISBN :
4-9901816-0-3
