Embedding PbS Quantum Dots (QDs) in Pb-Halide Perovskite Matrices: QD Surface Chemistry and Antisolvent Effects on QD Dispersion and Confinement Properties
Abstract
Hybrid materials of metal chalcogenide colloidal quantum dots (QDs) embedded in metal halide perovskites (MHPs) have led to composites with synergistic properties. Here, we investigate how QD size, surface chemistry, and MHP film formation methods affect the resulting optoelectronic properties of QD/MHP "dot-in-matrix" systems. We monitor the QD absorption and photoluminescence throughout synthesis, ligand exchange, and transfer into the MHP ink, and we characterize the final QD/MHP films via electron microscopy and transient absorption. In addition, we are the first to globally map how PbS QDs are distributed on the micrometer scale within these dot-in-matrix systems, using three-dimensional (3D) tomography time-of-flight secondary ion mass spectrometry. The surface chemistry imparted during synthesis directly affects the optical properties of the dot-in-matrix composites. Pb-halide passivation leads to QD/MHP dot-in-matrix samples with optical properties that are well-described by a theoretical model, based on a Type I finite-barrier heterostructure between the PbS QD and the MHP matrix. Samples without Pb-halide passivation show complicated size-dependent behavior, indicating a transition from a Type I heterostructure between the PbS QD wells and MHP barriers for small-sized QDs to PbS QDs that are electronically decoupled from the MHP matrix for larger QDs. Furthermore, the choice in perovskite antisolvent crystallization method leads to a difference in the spatial QD distribution within the perovskite matrix, differences in carrier lifetime, and photoluminescence shifts of up to 180 meV for PbS in methylammonium lead iodide. This work establishes an understanding of such emerging synergistic systems relevant for technologies such as photovoltaics, infrared emitters and detectors, and other unexplored technological applications.
Additional Information
© 2020 American Chemical Society. Received: July 7, 2020; Accepted: September 22, 2020; Published: September 22, 2020. This work is supported by the Center for Hybrid Organic Inorganic Semiconductors for Energy (CHOISE), an Energy Frontier Research Center funded by the Office of Science, Office of Basic Energy Sciences within the U.S. Department of Energy. E.A.G. acknowledges support from the Director's Fellowship within NREL's Laboratory Directed Research and Development (LDRD) program. Part of this work was authored by Alliance for Sustainable Energy, Limited Liability Company, the manager and operator of the National Renewable Energy Laboratory, under Contract No. DE-AC36-08GO28308. The views expressed in the article do not necessarily represent the views of the Department of Energy or the U.S. Government. The U.S. Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for U.S. Government purposes. The authors declare no competing financial interest.Attached Files
Supplemental Material - tz0c00302_si_001.pdf
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Additional details
- Alternative title
- Embedding PbS QDs in Pb-halide perovskite matrices: QD Surface chemistry and antisolvent effects on QD dispersion and confinement properties
- Eprint ID
- 105566
- DOI
- 10.1021/acsmaterialslett.0c00302
- Resolver ID
- CaltechAUTHORS:20200925-135425481
- National Renewable Energy Laboratory
- DE-AC36-08GO28308
- Department of Energy (DOE)
- Created
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2020-09-25Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field