Simple experimental test to distinguish extraction and injection barriers at the electrodes of (organic) solar cells with S-shaped current–voltage characteristics Wolfgang Tress and Olle Inganäs Linköping University Post Print N.B.: When citing this work, cite the original article. Original Publication: Wolfgang Tress and Olle Inganäs, Simple experimental test to distinguish extraction and injection barriers at the electrodes of (organic) solar cells with S-shaped current–voltage characteristics, 2013, Solar Energy Materials and Solar Cells, (117), SI, 599-603. http://dx.doi.org/10.1016/j.solmat.2013.07.014 Copyright: Elsevier http://www.elsevier.com/ Postprint available at: Linköping University Electronic Press http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-100304