Analysis of the electrochemical reactions and ions migration for crystalline silicon solar module under high system voltage

摘要

In this paper, the electrochemical reactions and ions migration of crystalline silicon solar module were investigated. Based on the different polarity system voltage, the equations of electrochemical reactions in crystalline silicon solar module were given out for the first time. A novel model was developed to quantify ions migration in crystalline silicon solar module. The outcome of calculation indicates that the migration time is mainly associated with the applied electric field and ambient temperature without regard to humidity. And the migration time across n+-p junction is far larger than that across SiNx:H layer, which suggests the migration of Na+ ions in perfect silicon is harder than that in SiNx:H layer, unless there exists stacking faults in n+-p junction. Finally, the transmission electron microscopy (TEM) was performed and that proves there exists a sparse distribution of Na+ ions in solar cells. The obtained results in this paper are beneficial to understand the electrochemical aging of module in the field.