Application of the Concept of Lifetime-Equivalent Defect Density in Defect Systems Comprising a Multitude of Defect Species

摘要

The specific injection dependence of either excess carrier lifetime or lifetime-equivalent defect density generally allows for the identification of a single defect species and the analysis of its properties. However, the presence of a multitude of defect species noticeably complicates this endeavor. A temporally different activation/deactivation dynamic of different defect species, as encountered in the context of light-induced degradation phenomena in crystalline silicon solar cells, in combination with the distinct injection dependence of specific defect species can help to distinguish the involved defect species. Within this simulation-based contribution, it is shown how injection-dependent information can be used to reveal the presence of a second defect species in the context of light-induced degradation and to distinguish clearly whether the formation of deep-level defects in the bulk or a deterioration in the surface passivation quality is responsible for an observed degradation of effective excess carrier lifetime.