Cracked Solar Cell Performance Depends on Module Temperature

Abstract

When cells in a crystalline silicon photovoltaic module crack, packaging materials hold the fragments together. Changes in module temperature cause cell fragments to move, allowing cracked metallization to lose and regain contact. We intentionally cracked cells in commercial PV modules and characterized the modules’ temperature-dependent electroluminescence (EL) response. Here we show that (1) metallization makes contact across cracks in a way that is temperature dependent and (2) this contact is not a function of temperature, but is hysteretic. We expect that any electro-optical characterization made at a single temperature will be misleading as to the effects of cracked cells at different temperatures. And we expect that a single temperature sweep cannot fully characterize the temperature dependence of electro-optical performance of modules with cracked cells.