Correlation between the metallization corrosion and acetic acid in crystalline silicon photovoltaic module
Taeko Semba
Abstract
Abstract This study investigates the effect of corrosion of the metallization containing lead tellurite glass frit used in solar cells due to acetic acid. When the c-Si photovoltaic (PV) module is operating in the new degradation mode, the electroluminescence (EL) dark area showed an increase in the series resistance that spreads around the bus bars. To understand metallization corrosion, a high-temperature and high-humidity test was conducted using PV modules. The metallization was observed with a scanning electron microscope. Observation of the metallization of the degraded module confirmed the generation of voids and gaps near the interface between the metallization and the Si wafer in the EL dark area. It was also observed that Te and Pb were mostly eluted from the glass frit components in the metallization during the acetic acid leaching test. The results suggest that the elution of Te by the acetic acid generates voids and gaps in the metallization.