1. State Key Lab of Electronic Thin Films and Integrated DevicesUniversity of Electronic Science and Technology of ChinaChengdu610054People's Republic of China
2. Efficient Power Conversion Corporation909 N. Sepulveda Blvd, Suite, 230EI SegundoCA90245USA
3. Department of Electronic and Computer EngineeringHong Kong University of Science and TechnologyKowloonHong KongPeople's Republic of China