1. Solar Cell Technology, Department of Materials Science and Engineering, Uppsala University, Box 534, SE-75121 Uppsala, Sweden
2. Renewable and Sustainable Energy Institute, University of Colorado, Boulder, Colorado 80309, United States
3. Centre for Materials Science and Nanotechnology/Department of Physics, University of Oslo, P.O.
Box 1048, Blindern, NO-0316 Oslo, Norway
4. Division of Applied Materials Physics, Department of Materials Science and Engineering, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden
5. Entropic Interface Group, Engineering Product Development, Singapore University of Technology and Design, 8 Somapah Road, Singapore 487372, Singapore