1. National‐Local Joint Engineering Laboratory of New Energy Photovoltaic DevicesResearch Center of Machine Vision Engineering of Hebei UniversityCollege of Electron and Information EngineeringCollege of Pharmaceutical ScienceKey Laboratory of Pharmaceutical Quality Control of Hebei ProvinceHebei University Baoding 071002 P. R. China
2. Department of Electrical and Computer EngineeringSouthern Illinois University Carbondale Carbondale 62901 IL USA
3. Department of Materials Science and EngineeringNational University of Singapore Singapore 117576 Singapore
4. Key Laboratory of Microelectronic Devices & Integrated Technology Institute of MicroelectronicsChinese Academy of Sciences Beijing 100029 P. R. China