Investigation of texturization for crystalline silicon solar cells with sodium carbonate solutions

We investigate a new texturization technique for crystalline silicon solar cells with sodium carbonate (Na2CO3 F) solutions. We show the dependence of the hemispherical surface reflectance on solution temperature, the etching time and the Na2CO3 concentration. Furthermore, we investigate what elemen t in Na2CO3 solution influences the texturing for reducing the texturing ti me. As a result of experiments, we find it possible to get low reflectance in a shorter texturing time by the addition of NaHCO3. The size of texture becomes smaller by the addition of NaHCO3 but the etching rate does not cha nge. We conclude carbonic ion and/or its compound seems to play an importan t role as the initiator of pyramidal structure. This texturing method is co st effective because there is no need of expensive IPA, and the surface ref lectance is reduced sufficiently in a short time. This method is promising for a large-scale production of crystalline silicon solar cells. (C) 2000 E lsevier Science B.V. All rights reserved.