Multiple exciton generation in tin–lead halide perovskite nanocrystals for photocurrent quantum efficiency enhancement

Yifan Chen, Jun Yin, Qi Wei, Chenhao Wang, Xiaoting Wang, Hui Ren, Siu Fung Yu, Osman Bakr, Omar F. Mohammed, Mingjie Li

Research output: Contribution to journalArticlepeer-review

40 Scopus citations


Multiple exciton generation (MEG), the generation of multiple electron–hole pairs from a single high-energy photon, can enhance the photoconversion efficiency in several technologies including photovoltaics, photon detection and solar-fuel production1,2,3,4,5,6. However, low efficiency, high photon-energy threshold and fast Auger recombination impede its practical application1,7. Here we achieve enhanced MEG with an efficiency of up to 87% and photon-energy threshold of two times the bandgap in highly stable, weakly confined formamidinium tin–lead iodide perovskite nanocrystals (FAPb1–xSnxI3 NCs; x ≤ 0.11). Importantly, an MEG-driven increment in the internal photocurrent quantum efficiency exceeding 100% with a low threshold is observed in such NC-sensitized photoconductors under ultraviolet-light illumination. The MEG enhancement mechanism is found to be mediated by the slower cooling and reduced trapping of hot carriers above the MEG threshold after the partial substitution of Pb by Sn. Our findings corroborate the potential importance of narrow-bandgap perovskite NCs for the development of optoelectronics that could benefit from MEG.
Original languageEnglish (US)
JournalNature Photonics
StatePublished - May 26 2022

Bibliographical note

KAUST Repository Item: Exported on 2022-05-30
Acknowledgements: M.L. acknowledges financial support from the Hong Kong Polytechnic University (grants 1-BE2Z, W188 and 1-ZVGH) and the Shenzhen Science, Technology and Innovation Commission (project no. R2021A064). J.Y., O.M.B. and O.F.M. acknowledge the Supercomputing Laboratory at KAUST for their efficient technical assistance.

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Electronic, Optical and Magnetic Materials


Dive into the research topics of 'Multiple exciton generation in tin–lead halide perovskite nanocrystals for photocurrent quantum efficiency enhancement'. Together they form a unique fingerprint.

Cite this