© 2014 American Chemical Society. New inorganic ligands including halide anions have significantly accelerated progress in colloidal quantum dot (CQD) photovoltaics in recent years. All such device reports to date have relied on halide treatment during solid-state ligand exchanges or on co-treatment of long-aliphatic-ligand-capped nanoparticles in the solution phase. Here we report solar cells based on a colloidal quantum dot ink that is capped using halide-based ligands alone. By judicious choice of solvents and ligands, we developed a CQD ink from which a homogeneous and thick colloidal quantum dot solid is applied in a single step. The resultant films display an n-type character, making it suitable as a key component in a solar-converting device. We demonstrate two types of quantum junction devices that exploit these iodide-ligand-based inks. We achieve solar power conversion efficiencies of 6% using this class of colloids.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUS-11-009-21
Acknowledgements: This publication is based in part on work supported by Award KUS-11-009-21, from 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. H.D. would like to acknowledge a scholarship from the China Scholarship Council (CSC). Computations were performed on the GPC supercomputer at the SciNet HPC Consortium. 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 Angstrom Engineering, Inc. and Innovative Technology, Inc. for useful discussions regarding material deposition methods and control of the glovebox environment, respectively. The authors thank L. Levine for CQD synthesis, L. Rollny for the zeta potential measurements, F. Fan for TEM measurements, J. McDowell for the XRD measurements, H. F. Movahed for SCAPS simulations, and E. Palmiano, R. Wolowiec, and D. Kopilovic for their help during the course of these studies.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.