Practical Considerations in Quantitative Dark and Illuminated Lock-in Thermography Analyses of Shunts in Silicon Thin-Film Modules

Abstract

In this study, dark and illuminated lock-in thermography (DLIT/ILIT) is applied for the investigation of state of the art a-Si:H/μc-Si:H tandem modules. The recent progress in LIT technology enables the collection of spatially highly resolved thermographs that permit a precise location of individual shunts. The possibility of illumination at two different wavelengths was applied to determine the origin of the shunts. Additionally, quantitative information can be gained by the investigation of local heating at different working points of the module. For illuminated lock-in thermography a significant contribution of thermalization and Peltier cooling due to the lateral current flow was observed, which has to be considered in regard to quantitative analyses.