New iridium(III) cyclometalates with extended absorption features for bulk heterojunction solar cells

Guiping Tan, Peng Liu, Hao Wu, Sze Chun Yiu, Fengrong Dai, Ying Hsuan Feng, Xiaotian Liu, Yongfu Qiu, Yih Hsing Lo, Cheuk Lam Ho, Wai Yeung Wong

Research output: Journal article publicationJournal articleAcademic researchpeer-review

7 Citations (Scopus)


Two new iridium(III) cyclometalates (A and B) based on 2-[5-(9,9′-diethyl-9H-fluoren-7-yl)thienyl]-pyridine were synthesized, characterized and applied in bulk-heterojunction solar cells (BHJSCs). Their absorption, electrochemical, thermal and photovoltaic properties have been investigated. The results reveal that the replacement of phenyl ring by thienyl one can extend the absorption wavelength up to 530 nm, thus narrowing the energy gap (Eg) to 2.93 eV and 2.81 eV for A and B, respectively. These complexes exhibit excellent thermal stability with the onset decomposition temperature at 5% weight-loss (Td) of over 370 °C. The BHJSC device with A as donor blended with [6,6]-phenyl C61-butyric acid methyl ester (PCBM) gave the best power conversion efficiency (η) of 0.51%, with a short-circuit photocurrent density (Jsc) of 2.68 mA cm-2, an open-circuit photovoltage (Voc) of 0.66 V and a fill factor (ff) of 0.28 under illumination of an AM 1.5 solar cell simulator.
Original languageEnglish
Pages (from-to)280-286
Number of pages7
JournalJournal of Organometallic Chemistry
Publication statusPublished - 15 Jun 2016
Externally publishedYes


  • Bulk-heterojunction solar cell
  • Iridium(III) complex
  • Phosphorescence
  • Photovoltaics
  • Thiophene

ASJC Scopus subject areas

  • Biochemistry
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry
  • Materials Chemistry

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