1. State
Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054, China
2. Institute
of Mineral Engineering, Division of Materials Science and Engineering,
Faculty of Georesources and Materials Engineering, RWTH Aachen University, 52064 Aachen, Germany
3. Aachen
Institute for Advanced Study in Computational Engineering Science
(AICES), RWTH Aachen University, 52062 Aachen, Germany