Nature Materials 8, 707–716 (2009); published online: 1 September 2009; corrected after print: 11 September 2009.

In Table 1 on page 709 of the above Progress Article, the structures for the compounds poly(3-hexylthiophene) (RRP3HT), tetraphenylporphyrin (TPP), pentacene, rubrene and copper phthalocyanine (CuPc) should have appeared as shown below. These errors have been corrected in the HTML and PDF versions.