Abstract
Colloidal quantum dots are emerging solution-processed materials for large-scale and low-cost photovoltaics. The recent advent of quantum dot inks has overcome the prior need for solid-state exchanges that previously added cost, complexity, and morphological disruption to the quantum dot solid. Unfortunately, these inks remain limited by the photocarrier diffusion length. Here we devise a strategy based on n- and p-type ligands that judiciously shifts the quantum dot band alignment. It leads to ink-based materials that retain the independent surface functionalization of quantum dots, and it creates distinguishable donor and acceptor domains for bulk heterojunctions. Interdot carrier transfer and exciton dissociation studies confirm efficient charge separation at the nanoscale interfaces between the two classes of quantum dots. We fabricate the first mixed-quantum-dot solar cells and achieve a power conversion of 10.4%, which surpasses the performance of previously reported bulk heterojunction quantum dot devices fully two-fold, indicating the potential of the mixed-quantum-dot approach.
Original language | English (US) |
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Journal | Nature Communications |
Volume | 8 |
Issue number | 1 |
DOIs | |
State | Published - Nov 6 2017 |
Externally published | Yes |
Bibliographical note
KAUST Repository Item: Exported on 2022-06-08Acknowledged KAUST grant number(s): KUS-11-009-21
Acknowledgements: This publication is based in part on work supported by an award (KUS-11-009-21) from the King Abdullah University of Science and Technology (KAUST), by the Ontario Research Fund Research Excellence Program and by the Natural Sciences and Engineering Research Council (NSERC) of Canada. We acknowledge T. Casagrande and B. Langelier for help with FIB sample preparation, conducted at Canadian Centre for Electron Microscopy (CCEM) of McMaster University, Computations were performed on the GPC supercomputer at the SciNet HPC Consortium. We also thank Y. Li and Professor Z-H Lu for UPS analysis. SciNet is funded by the Canada Foundation for Innovation under the auspices of Compute Canada; the Government of Ontario; Ontario Research Fund-Research Excellence; and the University of Toronto. We thank L. Levina, E. Palmiano, and D. Kopilovic for their help during the course of the study. J.Z.F. acknowledges support from NSERC Canada Graduate Scholarships. A.H.P. acknowledges support from the Fonds de recherche du Québec-Nature et technologies (FRQNT) and the Ontario Graduate Scholarship (OGS) program.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.
ASJC Scopus subject areas
- General Biochemistry, Genetics and Molecular Biology
- General Chemistry
- General Physics and Astronomy