2 Nanoscale Charge Transport and Internal Structure of Bulk Heterojunction Conjugated Polymer/Fullerene Solar Cells by Scanning Probe Microscopy J. Phys. Chem. C, 112 (18), 7241 -7249, 2008. 10.1021/jp712086q S1932-7447(71)02086-7 http://pubs.acs.org/cgi-bin/abstract.cgi/jpccck/2008/112/i18/abs/jp712086q.html