Cooperation studies have supported the understanding of possible technological development strategies adopted in the Research and Development (R&D) departments. This article introduces an approach associating Social Network Analysis and Salton measure to expand the analysis of inter-organizational cooperation networks. This approach was used in 37,122 patent families of photovoltaic (PV) technologies applied between 1998 and 2017. The results showed that patent assignees prioritize their developments exclusively in their internal R&D areas. It has been observed that closed innovation is more prevalent than open innovation, given the lower proportion of technologies developed in collaboration. When there is cooperation, they prioritize cooperation relations between organizations of the same nationality. Small companies have greater cooperation intensity than large ones because they are more dependent on the innovation ecosystem and seek growth and support for their technological development by partnerships. The intensity of this cooperation is classified as incipient, but smaller organizations have a unilateral dependence on the relationship, which is a clear definition of dominance in cooperative relations. The results regarding the intensity of cooperation and the mapping of these networks did not indicate different actors who assumed more significant roles, whether in terms of constancy, centrality or intermediations of these relations. The findings can support strategic decisions on R&D, prioritization of investments, identification of potential partnerships (or competitors) for technological development. Additionally, they can contribute to the definition of public policies based on promoting the development and use of PV technologies.