Performance Assessment of Cell-Separation Processes for Rear-Contact Solar Cells: Comparison of Indoor and Outdoor Measurements

Abstract

Half-cell and third-cell modules are the current module technology standard due to their enhanced electrical performance. Also, special module layouts for building or vehicle integrated photovoltaics rely on non-standard cell formats obtained by separation techniques. For either application, interdigitated back-contact (IBC) solar cells are one of the promising cell technologies due to their higher performance and more aesthetic appearance. Thus, a cell separation process, usually employing laser tools, is needed that splits the cells as partial cells are manufactured from full cells. However, this cell cutting also induces additional electrical losses. In this work, we analyze the performance of third cell mini-modules made of IBC cells in comparison to PERC cells as reference. Under standard test conditions (STC), an overall performance gain can only be found for the PERC cells, while current and recombination losses dominate the IBC mini-modules. Outdoor measurements under non-STC conditions reveal reduced performance gains under lower illumination. We show a detailed analysis regarding the performance differences of the IBC and PERC cell technologies at indoor STC and outdoor non-STC test conditions.