Light-induced degradation variation in industrial multicrystalline PERC silicon solar cells

Light and elevated temperature induced degradation (LeTID) varies significantly in multicrystalline PERC silicon solar cells, depending mainly on the solar cell processes. We show that despite high firing temperatures, LeTID can manifest itself in two different ways: 1) strong LeTID in good grains (jsc and Voc losses >7%rel.), or 2) low LeTID in good grains with stronger LeTID at dislocation clusters. Such LeTID at dislocation clusters is not only caused by a bulk recombination increase but also by an increased back-surface recombination velocity.