1. School of Chemical Sciences, University of Auckland, 23 Symonds Street, Auckland 1142, New Zealand
2. The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
3. Polymer Electronics Research Centre (PERC), School of Chemical Sciences, University of Auckland, 23 Symonds Street, Auckland 1142, New Zealand
4. Department of Physics, University of Auckland, 23 Symonds Street, Auckland 1142, New Zealand