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Exploring Technology Evolution in the Solar Cell Field: An Aspect from Patent Analysis

Abstract The identification and tracking of technology trends in an industry is crucial for effective information management, as well as for companies to maintain their competitive edge in a changing technological environment. A novel method that combines patentometrics, time series analysis, and social network analysis is proposed to capture the evolution of technology topics and to monitor the vicissitudes of dominators. Taking patents in the solar cell field as an example, a total of 3,820 patents issued between 1997 and 2011 were collected from the United States Patent and Trademark Office database. We divided the examined time span into five 3-year periods, during which the technology dominators, who are the major contributors of patents in a technological field, were identified. These key assignees were also classified as stable, appearing, or exiting based on their transition patterns from one time period to the next. Results show that solar cell patents can be grouped into eight major technology communities, and that the frequency of change in technology dominators across the years varied for each community. We further examined the relationship between a technology dominator’s transition pattern and the changes in its patent characteristics. The appearing technology dominators were found to have increased values for several patent characteristics, including science linkage, pendency period, originality index, and endogeneity index, while their technology cycle time decreased; the stable technology dominators exhibited decreasing science linkage and originality index values; and exiting technology dominators showed trends in patent characteristics that were opposite to that of the appearing technology dominators. By using the methodology proposed in this study, companies can gain critical insights into the major trends of a technological field, which would be invaluable to the planning and assessment of a company’s research-and-development strategies.