Long Term Performance of PV Modules: System Optimization through the Application of Innovative Non-Destructive Characterization Methods

Abstract

Innovative and highly sensitive analytical tools for the non-destructive detection and visualization of defects, delamination and material incompatibilities within the multi-material laminate of a PV-module are presented. The presence and position of physical imperfections such as delamination, voids or impurities within a module were determined with Pulse Thermography (PT) and Scanning Acoustic Microscopy (SAM). With SAM it is also possible to identify cracks within a wafer very accurately, as could be demonstrated in a comparative measurement with Electroluminescence (EL) experiments. For the non-destructive identification of chemical changes in the individual layers of a PV-module - caused by degradation, decomposition or impurities - confocal Raman microscopy has proven to be a very powerful tool.