1. Department of Materials Engineering, The University of British Columbia (UBC), Vancouver, Canada
2. Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, Taiwan
3. Department of Electrical and Computer Engineering, The University of British Columbia (UBC), Vancouver, Canada
4. Fraunhofer Institute for Solar Energy Systems (ISE), Freiburg im Breisgau, Germany
5. Graduate Institute of Photonics and Optoelectronics, Graduate School of Advanced Technology, National Taiwan University, Taipei, Taiwan