Investigation of Texturization for Monocrystalline Silicon Solar Cells with Na2CO3 and NaHCO3 Solutions

Abstract

In this paper, a promising texturization technique for monocrystalline silicon solar cells with sodium carbonate and sodium bicarbonate solutions has been investigated. A series of comparative experiments with different parameters, such as the concentration of Na2CO3 and NaHCO3, the solution temperature and the etching time were made to indicate the dependence of hemispherical surface reflectance. After four groups of experiments, we have obtained uniform and reliable pyramidal texturization on different silicon surfaces. Furthermore, we find it possible to get a better pyramidal structure by the addition of NaHCO3. A mixed solution consisting of 20 wt% sodium carbonate and 4 wt% sodium bicarbonate at 85°C for 30 min has been found that generates a homogeneous pyramidal structure on the silicon surface. The textured silicon surface exhibits a lower average reflectivity (about 12.84%) in the main range of solar spectrum (400 nm-800 nm). Because this texturization method is economical, nonhazardous and has low pollution. We feel that it is suitable for the large-scale production.