The main issues confronting people of the 21st century are said to be energy, the environment and resources. Consequently, solar cell research is an attractive research field from both an academic and industrial viewpoint. Organic solar cells made from organic materials such as conjugated polymers and fullerenes convert photon energy to electric current through a principle that differs from silicon-based solar cells. Organic solar cells also have many outstanding features, and as such are currently being actively researched. In addition to understanding the primary processes such as exciton generation and charge separation and recombination on a molecule’s temporal scale, it is also absolutely imperative to design and build a precise device structure on a molecule’s spatial scale in order to control these primary processes and achieve high conversion efficiency. As such, at our research laboratory we use transient absorption spectroscopy based on ultrashort pulsed lasers to observe transient species from exciton generation through to charge collection to each electrode over a wide time scale, and elucidate on a molecule’s temporal scale the mechanisms that lead to the photon-to-current energy conversion. Furthermore, using technology for the fabrication of ultrathin polymer films we are attempting to design the layered structure on a molecule’s spatial scale and control these primary processes. In this way, we can understand the structure and mechanism of organic solar cells, and carry out research to develop new organic solar cells with improved performance. [Dynamics of Excitons and Charged Carriers in Polymer Solar Cells] ![]() Recent Publications 1. S. Yamamoto, J. Guo, H. Ohkita, S. Ito, Adv. Funct. Mater., 18, 2555-2562 (2008). 2. T. A. Ford, H. Ohkita, S. Cook, J. R. Durrant, N. C. Greenham, Chem. Phys. Lett., 454, 237-241 (2008). 3. H. Ohkita, S. Cook, Y. Astuti, W. Duffy, S. Tierney, W. Zhang, M. Heeney, I. McCulloch, J. Nelson, D. D. C. Bradley, J. R. Durrant, J. Am. Chem. Soc., 130, 3030-3042 (2008). 4. S. Cook, H. Ohkita, Y. Kim, J. J. Benson-Smith, D. D. C. Bradley, J. R. Durrant, Chem. Phys. Lett., 445, 276-280 (2007). 5. H. Ohkita, S. Cook, Y. Astuti, W. Duffy, M. Heeney, S. Tierney, I. McCulloch, D. D. C. Bradley, J. R. Durrant, Chem. Commun., 3939-3941 (2006). 6. S. Cook, H. Ohkita, J. R. Durrant, Y. Kim, J. J. Benson-Smith, J. Nelson, D. D. C. Bradley, Appl. Phys. Lett., 89, 101128/1-101128/3 (2006). 7. H. Ohkita, S. Cook, T. A. Ford, N. C. Greenham, J. R. Durrant, J. Photochem. Photobiol. A, 182, 225-230 (2006).
[Nanometric Design of Highly Efficient Polymer Solar Cells with Ultrathin Films] ![]() Recent Publications 1. M. Ogawa, M. Tamanoi, H. Ohkita, H. Benten, S. Ito, Sol. Energy Mater. Sol. Cells, DOI:10.1016/j.solmat.2008.11.050. 2. K. Masuda, M. Ogawa, H. Ohkita, H. Benten, S. Ito, Sol. Energy Mater. Sol. Cells, DOI:10.1016/j.solmat.2008.09.028. 3. H. Benten, N. Kudo, H. Ohkita, S. Ito, Thin Solid Films, in press. 4. H. Benten, M. Ogawa, H. Ohkita, Shinzaburo Ito, Adv. Funct. Mater., 18, 1563-1572 (2008). 5. M. Ogawa, N. Kudo, H. Ohkita, S. Ito, H. Benten, Appl Phys Lett, 90, 223107/1-223107/3 (2007).
[Development of Organic-Inorganic Hybrid Solar Cells] ![]() Recent Publications 1. N. Kudo, S. Honda, Y. Shimazaki, H. Ohkita, S. Ito, H. Benten, Appl. Phys. Lett., 90, 183513/1-183513/3 (2007). 2. N. Kudo, Y. Shimazaki, H. Ohkita, M. Ohoka, S. Ito, Sol. Energy Mater. Sol. Cells, 91, 1243-1247 (2007). 3. H. Ohkita, Y. Shimazaki, M. Ohoka, S. Ito, Chem. Lett., 33, 1598 (2004). Back to page top |