Cobalt dopant with deep redox potential for organometal halide hybrid solar cells

Teck Ming Koh, Sabba Dharani, Hairong Li, Rajiv Ramanujam Prabhakar, Nripan Mathews*, Andrew C. Grimsdale, Subodh G. Mhaisalkar

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

56 Citations (Scopus)

Abstract

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 dopant possesses, to the best of our knowledge, the deepest redox potential among all cobalt-based dopants used in solar cell applications, allowing it to dope a wide range of hole-conductors. We demonstrate the tuning of redox potential of the Co dopant by incorporating pyrimidine moiety in the ligand. We characterize the optical and electrochemical properties of the newly synthesized dopant and show impressive spiro-to-spiro+ conversion. Lastly, we fabricate high efficiency perovskite-based solar cells using MY11 as dopant for molecular hole-conductor, spiro-OMeTAD, to reveal the impact of this dopant in photovoltaic performance. An overall power conversion efficiency of 12 % is achieved using MY11 as p-type dopant to spiro-OMeTAD. Superiority complex: A new cobalt complex with deep redox potential is synthesized as p-dopant for hole-transporting materials in photovoltaic devices. High efficiency perovskite-based solar cells are fabricated using the complex as dopant for molecular hole-conductor 2,2′,7,7′-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9′-spirobifluorene. The dopant shows effective spiro-to-spiro+ conversion and excellent dopant properties in photovoltaic applications.

Original languageEnglish
Pages (from-to)1909-1914
Number of pages6
JournalChemSusChem
Volume7
Issue number7
DOIs
Publication statusPublished - Jul 2014
Externally publishedYes

ASJC Scopus Subject Areas

  • Environmental Chemistry
  • General Chemical Engineering
  • General Materials Science
  • General Energy

Keywords

  • cobalt complex
  • dye-sensitized solar cells
  • electrochemistry
  • perovskites
  • redox potential

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