1. Solar and Photovoltaics Engineering Research Center; Division of Physical Sciences and Engineering; King Abdullah University of Science and Technology (KAUST); Thuwal 23955-6900 Kingdom of Saudi Arabia
2. Photonics Laboratory; Computer, Electrical, and Mathematical Sciences and Engineering; KAUST; Thuwal 23955-6900 Kingdom of Saudi Arabia
3. Mathematical Institute; University of Oxford; Woodstock Road Oxford OX2 6GG UK