1. Department of PhotovoltaicsInstitute for Solar Energy Research Hamelin (ISFH) Am Ohrberg 1 Emmerthal 31860 Germany
2. Department of Solar EnergyInstitute of Solid-State PhysicsLeibniz University Hannover Appeltr. 2 Hannover 30167 Germany
3. Global Wafers via Nazionale 59 Merano 39012 Italy
4. 4 Harrison's Lane Woodstock OX20 1SS UK