The importance of two major issues (i.e., global warming and energy shortage) draws attention to many countries and scholars in recent years. Therefore, many countries start to carry out researches in the field of Green Energy Industry. The main objective of the Green Energy Industry is to reduce the crisis of global warming and to find alternative energy sources to solve energy shortage issue. In Green Energy Industry, the Solar Industry is the major development focus in many countries. The Solar Industry in Taiwan mainly focuses on solar cell; the issue of lacking raw materials in the past that results in high production cost and production pollution is not yet solved, but the industry proactively and continuously to innovate and research to overcome problems that exists in the industry. Based on the U.S. patent database, this study collects and discusses information of the third-generation DSSC (dye-sensitized solar cell) from the United States, Japan, Germany, Spain and Taiwan; as well as to perform the structural analysis of patentees and company matrix with Ucinet software in social network analysis (SNA), so that we can understand if the patentees from these five countries use the management model of open innovation for knowledge flow and technology development in the industry. This study discovers that Japan mainly focuses on open innovation and uses it as the operational strategy in DSSC (dye-sensitized solar cell) industry, so that it is able to cooperate with other industries and allows them to understand the technology and the main patent technology is H01G009; in addition to the knowledge flow between enterprises, this study also discovers that the patentees can easily have knowledge flow between the research unit, subsidiary and parent company. Further, using patent citing understand four conntry knowledge flow and this main technology development to Japan. This study expected to provide a reference for the industry, government and academia, so that they will understand the importance of knowledge, specialist cultivation and future development in the industry.
