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Ligand-assisted cation-exchange engineering for high-efficiency colloidal Cs1-xFAxPbI3 quantum dot solar cells with reduced phase segregation

Journal Article


Abstract


  • The mixed caesium and formamidinium lead triiodide perovskite system (Cs1−xFAxPbI3) in the form of quantum dots (QDs) offers a pathway towards stable perovskite-based photovoltaics and optoelectronics. However, it remains challenging to synthesize such multinary QDs with desirable properties for high-performance QD solar cells (QDSCs). Here we report an effective oleic acid (OA) ligand-assisted cation-exchange strategy that allows controllable synthesis of Cs1−xFAxPbI3 QDs across the whole composition range (x = 0–1), which is inaccessible in large-grain polycrystalline thin films. In an OA-rich environment, the cross-exchange of cations is facilitated, enabling rapid formation of Cs1−xFAxPbI3 QDs with reduced defect density. The hero Cs0.5FA0.5PbI3 QDSC achieves a certified record power conversion efficiency (PCE) of 16.6% with negligible hysteresis. We further demonstrate that the QD devices exhibit substantially enhanced photostability compared with their thin-film counterparts because of suppressed phase segregation, and they retain 94% of the original PCE under continuous 1-sun illumination for 600 h.

UOW Authors


  •   Cheng, Ningyan (external author)
  •   Du, Yi
  •   Ren, Long (external author)

Publication Date


  • 2020

Citation


  • Hao, M., Bai, Y., Zeiske, S., Ren, L., Liu, J., Yuan, Y., . . . Wang, L. (2020). Ligand-assisted cation-exchange engineering for high-efficiency colloidal Cs1-xFAxPbI3 quantum dot solar cells with reduced phase segregation. Nature Energy, 5(1), 79-88. doi:10.1038/s41560-019-0535-7

Scopus Eid


  • 2-s2.0-85078237247

Web Of Science Accession Number


Start Page


  • 79

End Page


  • 88

Volume


  • 5

Issue


  • 1

Abstract


  • The mixed caesium and formamidinium lead triiodide perovskite system (Cs1−xFAxPbI3) in the form of quantum dots (QDs) offers a pathway towards stable perovskite-based photovoltaics and optoelectronics. However, it remains challenging to synthesize such multinary QDs with desirable properties for high-performance QD solar cells (QDSCs). Here we report an effective oleic acid (OA) ligand-assisted cation-exchange strategy that allows controllable synthesis of Cs1−xFAxPbI3 QDs across the whole composition range (x = 0–1), which is inaccessible in large-grain polycrystalline thin films. In an OA-rich environment, the cross-exchange of cations is facilitated, enabling rapid formation of Cs1−xFAxPbI3 QDs with reduced defect density. The hero Cs0.5FA0.5PbI3 QDSC achieves a certified record power conversion efficiency (PCE) of 16.6% with negligible hysteresis. We further demonstrate that the QD devices exhibit substantially enhanced photostability compared with their thin-film counterparts because of suppressed phase segregation, and they retain 94% of the original PCE under continuous 1-sun illumination for 600 h.

UOW Authors


  •   Cheng, Ningyan (external author)
  •   Du, Yi
  •   Ren, Long (external author)

Publication Date


  • 2020

Citation


  • Hao, M., Bai, Y., Zeiske, S., Ren, L., Liu, J., Yuan, Y., . . . Wang, L. (2020). Ligand-assisted cation-exchange engineering for high-efficiency colloidal Cs1-xFAxPbI3 quantum dot solar cells with reduced phase segregation. Nature Energy, 5(1), 79-88. doi:10.1038/s41560-019-0535-7

Scopus Eid


  • 2-s2.0-85078237247

Web Of Science Accession Number


Start Page


  • 79

End Page


  • 88

Volume


  • 5

Issue


  • 1