Series resistance imaging of solar cells by voltage dependent electroluminescence

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 Phi(i)(U) and its derivative Phi(i)'(U) with respect to the applied voltage U. The combined analysis of these two quantities yields the local series resistance R-i(se) and proves the physical validity of the used current transport model and thus the physical relevance of the determined R-i(se) value. The method is verified on a monocrystalline silicon solar cell with local shunts and local series resistance problems. (C) 2007 American Institute of Physics.