In the collaborative research of Kao Corporation, The University of Tokyo, and Kyushu Institute of Technology,
Fabrication technology of solar cells having potential for high power conversion efficiency has been developed

A collaborative research group comprised of Material Science Research, Kao Corporation (President Michitaka Sawada), Research Center for Advanced Science and Technology, The University of Tokyo (President Makoto Gonokami), and Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology (President Yuji Oie) has successfully developed a fabrication technology of intermediate-band solar cells by a solution process for the first time in the world.

A collaborative research group comprised of Material Science Research of Kao Corporation, Professor Yoshitaka Okada and Assistant Professor Ryo Tamaki at the Research Center for Advanced Science and Technology, University of Tokyo, and Professor Shuzi Hayase and Assistant Professor Yuhei Ogomi at the Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, is conducting research and development of solar energy conversion technology (solar cells, etc.) in order to realize a sustainable society. The intermediate-band solar cell (IBSC) containing a nano-architecture (photo-absorption layer) where semiconductor nano-crystallites (quantum dots) are dispersed in a bulk semiconductor matrix has potential for high power conversion efficiency (PCE). Presently, IBSCs have been fabricated only by a "dry process". However, it is generally difficult to improve the PCE and to reduce manufacturiung cost because of restrictions on the available materials and of facility capacity. This research group succeeded to develop an elemental technology for fabrication of IBSCs in a "solution process" by using our core-technologies such as "control of nano-interface, dispersion, and crystallization in solutions" and "characterization and analysis of solar cells" (Fig. 1). The present results pave the way towards not only high PCE but also low cost, light, and flexible IBSCs which can contribute to realizing a sustainable society.