For crystalline silicon solar cells, front-side electrodes commonly consist of silver particles printed in fine lines containing metal-oxide glasses designed to etch through the insulating Si:N anti-reflective thin film during a sintering process. Photovoltaic cell efficiency is strongly affected by the complex, engineered interface between the conductive electrode and the active material, both at the time of production and as the PV module ages during extended environmental exposure. The development of new analytical methods to characterize ion-migration, metal deposition and corrosion is important to our understanding of how the choice of photovoltaic (PV) materials affects module efficiency and performance in different service environments.<br/><br/>Laser ablation ICP-MS offers the unique ability to characterize the bulk chemistry in spatially localized areas on the order of 10-40 mm in diameter. A focused laser beam is scanned across the surface of interest generating an aerosol of solid particles which are ionized with an Ar plasma. The resulting ions, ranging from Li to Bi, are mass analyzed with detection limits that are element and matrix specific extending to the ppm levels. LA-ICP-MS methodology has been developed and applied to characterize the elemental chemical distribution within as produced fine silver electrodes, as well as silver electrodes in aged modules collected from the field. In one case, quantitative analysis of trace metal-oxide additive concentrations in sintered silver electrodes was accomplished through the development of matrix-matched reference samples. In another example, ion enrichment profiles were determined at the PV cell / polymeric encapsulant interface following accelerated testing for potential induced module defects. Details of the LA-ICP-MS measurements and results from these two examples will be discussed in this presentation.

Photovoltaic module characterization using laser ablation ICP-MS

252nd National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.