1. Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
2. National Renewable Energy Laboratory, Golden, Colorado 80401, USA
3. CNRS, Institut Photovoltaïque d’Ile de France (IPVF), UMR 9006 Palaiseau, France
4. Department of Engineering, Hope College, Holland, Michigan 49423, USA
5. Materials Science and Engineering Program, University of Colorado Boulder, Boulder, Colorado 80309, USA
6. Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, Colorado 80309, USA
7. Department of Electrical, Computer, and Energy Engineering, University of Colorado Boulder, Boulder, Colorado 80309, USA
8. Andlinger Center for Energy and the Environment, Princeton University, Princeton, New Jersey 08544, USA