1. Department of Material Science and Engineering, University of Wisconsin - Madison, Madison, Wisconsin 53706, United States
2. Departments of Radiology and Medical Physics, University of Wisconsin - Madison, Madison, Wisconsin 53705, United States
3. Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430073, China
4. University of Wisconsin Carbone Cancer Center, Madison, Wisconsin 53705, United States
5. State Key Laboratory of Thin Films and Integrated Devices, School of Optical Science and Engineering, University of Electronic Science and Technology of China, Chengdu 610054, China