Optimization of sodium carbonate texturization on large-area crystalline silicon solar cells

This work describes a texturization method for monocrystalline silicon solar cells based on a mixture of sodium carbonate and sodium hydrogen carbonate solutions. A specific solution has been found that results in an optimal etching rate, the lowest surface reflectance and a homogeneous density of pyramidal structures on the silicon surface. The subsequent phosphorus diffusion with rapid thermal processes has been modified in order to drastically reduce the process time and, simultaneously, to obtain a high homogeneity of the sheet resistance values and improved photocarriers lifetimes. 100 x 100 mm solar cells with an efficiency of 15.8% have been obtained compared to an efficiency of 14.7% for the reference cell. (c) 2007 Elsevier B.V. All rights reserved.