SPLTRAK Abstract Submission
Contribution of Na+ from Glass to PID-s in Solar Modules: Na Migration in EVA
Jacob A. Clenney1, Erick Martinez Loran2, Guillaume von Gastrow3, Tanguy Terlier4, David P. Fenning2, Rico Meier1, Mariana I. Bertoni1
1Arizona State Univeristy, Phoenix, AZ, United States
/2University of California San Diego, La Jolla, CA, United States
/3SunPower Corp, San Jose, CA, United States
/4Rice University, Houston, TX, United States

Sodium induced shunting continues to be a challenging issue in crystalline Si solar modules. Potential-Induced Degradation of the Shunting type (PID-s) has been linked to Na, but the source is unclear. In this paper we evaluate the ion migration kinetics in encapsulant material under operational conditions. Analysis of Na migration profiles reveal the diffusivity constant and activation energy of Na in EVA. Implementing these results in breakthrough time simulations indicates that Na migration from the glass through EVA is too slow to account for experimentally observed PID-s degradation indicating contamination during production as the most likely source.