Polarization Effects and Tests for Crystalline Silicon Cells

Polarization or the potential induced degradation effect (PID) on crystalline silicon moduls is an alarming failure mode on modern crystalline silicon cells meeting high system voltages [1-4]. It can cause power losses in the vicinity 30% and more. Known parameters for PID on the cell level are high electrical resistivity of the SiNx antireflective coating via low refractive index and increased thickness and low emitter depth. In this work we investigate the Polarization effect in regards to degradation speed on different encapsulants and module designs and with a special focus on selective emitter cells. The aim is a better understanding of the effect to propose appropriate test procedures for crystalline silicon cells and modules. For this purpose, different cells and modules have undergone various test sequences comparing different module materials and components.