Cobalt Dopant with Deep Redox Potential for Organometal Halide Hybrid Solar Cells

• DOI: 10.1002/cssc.201400081
• Publication Date: 2014-05-21T20:32:05Z
• Authors: Teck Ming Koh; Sabba Dharani; Hairong Li; Rajiv Ramanujam P...; Nripan Mathews; Andrew C. Grimsdale; Subodh G. Mhaisalkar
• Keywords: Moiety

In this work, we report a new cobalt(III) complex, tris[2-(1H-pyrazol-1-yl)pyrimidine]cobalt(III) tris[bis(trifluoromethylsulfonyl)imide] (MY11), with deep redox potential (1.27 V vs NHE) as dopant for 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD). This possesses, to the best of our knowledge, deepest among all cobalt-based dopants used in solar cell applications, allowing it dope wide range hole-conductors. We demonstrate tuning Co by incorporating pyrimidine moiety ligand. characterize optical and electrochemical properties newly synthesized show impressive spiro-to-spiro(+) conversion. Lastly, fabricate high efficiency perovskite-based cells using MY11 molecular hole-conductor, spiro-OMeTAD, reveal impact photovoltaic performance. An overall power conversion 12% is achieved p-type spiro-OMeTAD.