1. Photovoltaic Materials and Devices group Delft University of Technology 2628 CD Delft The Netherlands
2. Shenzhen Institute of Wide-bandgap Semiconductors Shenzhen 518055 China
3. Instituto de Micro y Nanoelectrónica Universidad San Francisco de Quito Quito 170 901 Ecuador
4. Institute of Photoelectronic Thin Film Devices and Technology Nankai University Tianjin 300350 China