Series resistance imaging of solar cells by voltage dependent electroluminescence

Abstract

This letter introduces a method based on electroluminescence imaging to determine mappings of the local series resistance of large area semiconductor devices such as solar cells. The method combines the local electroluminescence emission Φi(U) and its derivative Φi′(U) with respect to the applied voltage U. The combined analysis of these two quantities yields the local series resistance Rise and proves the physical validity of the used current transport model and thus the physical relevance of the determined Rise value. The method is verified on a monocrystalline silicon solar cell with local shunts and local series resistance problems.