Efficient cathode interfacial materials based on triazine/phosphine oxide for conventional and inverted organic solar cells

Um Kanta Aryal, Saripally Sudhaker Reddy, Jungmin Choi, Chae Young Woo, Seokhoon Jang, Youngu Lee, Bong Soo Kim, Hyung Woo Lee, Sung-Ho Jin

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1 Citation (Scopus)


Cathode interfacial layers (CIL) have been applied in organic solar cells (OSCs) for the enhancement of photovoltaic characteristics. Most of them are employed in either conventional organic solar cells (COSCs) or inverted organic solar cells (IOSCs) only. Herein, we have designed and synthesized two cathode interfacial materials, namely, 3-(4,6-bis(4-bromophenoxy)-1,3,5-triazin-2-yl)-2,6-difluorophenyl)diphenylphosphine oxide (Br-PO-TAZ) and 4,4′-((6-(3-(diphenylphosphoryl)-2,4-difluorophenyl)-1,3,5-triazine-2,4-diyl)bis(oxy))dibenzonitrile (CN-PO-TAZ), and utilized them as CILs for both COSCs and IOSCs. The incorporation of our new CIL layers significantly enhanced the photovoltaic performance compared to COSCs and IOSCs without the CILs. The CN-PO-TAZ exhibited a power conversion efficiency (PCE) of 8.19% for COSCs and 8.33% for IOSCs, whereas Br-PO-TAZ yielded a PCE of 8.15% for COSCs and 8.23% for IOSCs, respectively. The improved performance was attributed to the multiple favorable factors: significantly reducing leakage current, decreasing series resistance, suppressing recombination, efficient charge transport and collection. Moreover, the CIL layers helped for sustaining device stability because they served as an internal shield against humidity.[Figure not available: see fulltext.].

Original languageEnglish
Pages (from-to)727-732
Number of pages6
JournalMacromolecular Research
Issue number8
Publication statusPublished - Jul 2020
Externally publishedYes


  • cathode interfacial layers
  • conventional/inverted
  • organic solar cell
  • stability
  • triazine/phosphine oxide unit

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