Growth of High-Quality Superconducting FeSe0.5 Te0.5 Thin Films Suitable for Angle-Resolved Photoemission Spectroscopy Measurements via Pulsed Laser Deposition*Supported by the Chinese Academy of Sciences under Grant No 2010Y1JB6, the National Basic Research Program of China under Grant No 2010CB923000, and the National Natural Science Foundation of China under Grant Nos 11234014 and 11227903. (August 2015)