Abstract
Singlet exciton fission allows for the generation of two triplet excitons for each photon absorbed within an organic semiconductor. Efficient harvesting of these triplets could allow for the Shockley-Queisser limit on the power conversion efficiency of single-junction photovoltaics to be broken. Here, we show that singlet fission molecules bound directly to PbS quantum dots as ligands can undergo singlet fission with near unity efficiency and can transfer triplets sequentially into the PbS with near unity efficiency. Within the PbS, the excitations recombine, giving rise of the emission of photons. This allows for the doubling of the quantum dot photoluminescence quantum efficiency when photons are absorbed by the singlet fission ligand, as compared to when directly absorbed in the quantum dot. Our approach demonstrates that it is possible to convert the exciton multiplication process of singlet fission into a photon multiplication process and provides a new path to harness singlet fission with photovoltaics.
| Original language | English |
|---|---|
| Pages (from-to) | 1454-1460 |
| Number of pages | 7 |
| Journal | Journal of Physical Chemistry Letters |
| Volume | 9 |
| Issue number | 6 |
| DOIs | |
| State | Published - Mar 15 2018 |
Bibliographical note
Funding Information:N.J.L.K.D. acknowledges the Ernest Oppenheimer fund for an Oppenheimer Early Career Research Fellowship. J.R.A. acknowledges Cambridge Commonwealth European and International Trust for financial support. J.X. acknowledges EPSRC CDT in Nanoscience and Nanotechnology for financial support. The authors thank the Winton Programme for the Physics of Sustainability and the Engineering and Physical Sciences Research Council for funding. The data underlying this publication are available at https://doi.org/10.17863/ CAM.20890.
Publisher Copyright:
© 2018 American Chemical Society.
ASJC Scopus subject areas
- Materials Science (all)
- Physical and Theoretical Chemistry