Characterization of defects in PV devices is very important for the improvement of their performance over the long term.
A fast, efficient and non-destructive method has been developed for the detection and characterization of delamination in PV modules using active infrared thermography approach. Thermal image and transient thermal contrast evolution profile provide the qualitative as well as quantitative estimation of the severity of delamination in PV modules. This method can be applied in the production unit and outdoor field conditions.
In order to have spatially-resolved characterization of solar cells and modules, techniques like light beam induced current (LBIC), electroluminescence imaging (ELI) and lock-in thermography (LIT) have been used under different operating conditions which enhance their capabilities to identify the various types of defects and design failures in PV modules responsible for power loss.
This study involves the analysis of degradation effects in PV modules when they are exposed to harsh environmental conditions. IV characterization, EL and DLIT techniques have been used to investigate the various kind of defects and their growth over the time. By comparing EL and DLIT images, the influence of defects on the electrical parameters can also be studied. This study will be helpful in understanding the performance and reliability of modules and predicting module lifetime.