Comparison of XBIC and LBIC measurements of a fully encapsulated c-Si solar cell

A fully encapsulated c-Si solar cell was evaluated using focused X-ray and laser beams to probe the microscopic electrical performance and composition. Particular emphasis was placed on the influence of the silver fingers on the laser (LBIC) and X-ray beam induced current (XBIC). Therefore, an uncommonly high X-ray energy of 28keV was utilized for maximum sensitivity to the Ag distribution measured by X-ray fluorescence through the back sheet. The direct comparison of LBIC and XBIC measurements yields a comprehensive picture of these techniques, illustrating the advantages and challenges of both approaches. Specifically, the effect of heavy elements acting as a secondary photon source that increase the XBIC signal is discussed and supported by Monte-Carlo simulations.