1. PRIMALIGHT Faculty of Electrical Engineering King Abdullah University of Science and Technology (KAUST) Thuwal 23955‐6900 Saudi Arabia
2. School of Materials and Energy University of Electronic Science and Technology of China (UESTC) Chengdu Sichuan China
3. University of Zurich Physik‐Institut, Winterthurerstrasse 190 Zurich CH‐8057 Switzerland