Knowledge flows in the solar photovoltaic industry: Insights from patenting by Taiwan, Korea, and China

In this paper we extend work previously undertaken in industries such as semiconductor and flat panel displays to investigate knowledge flows from advanced countries (US, Japan and Europe) to catch-up follower countries (Taiwan, Korea and China), this time in the emergent solar photovoltaic industry. The solar photovoltaic industry is of particular interest in that it is poised between exploitation of first generation (crystalline silicon technologies) and new thin film and organic compound technologies, thus providing distinct sources of knowledge flow as measured by patent citations and linkage. For this study, we deploy a new database of 19,105 solar photovoltaic patents taken out by Taiwan, Korea and China at the USPTO over the 24 years 1984-2008, and analyse the knowledge flows revealed in these patents using a set of 12 International Patent Classification technology categories that we constructed. We demonstrate commonalities in patterns of knowledge flow between solar photovoltaic and earlier industries, but also suggestive differences, such as rising dependence of the catch-up countries on their own intra-national knowledge generation and flow, indicating their shift from imitation to innovation.