Abstract
Lead halide perovskite nanocrystals, such as CsPbBr3, exhibit efficient photoluminescence (PL) up-conversion, also referred to as anti-Stokes photoluminescence (ASPL). This is a phenomenon where irradiating nanocrystals up to 100 meV below gap results in higher energy band edge emission. Most surprising is that ASPL efficiencies approach unity and involve single-photon interactions with multiple phonons. This is unexpected given the statistically disfavored nature of multiple-phonon absorption. Here, we report and rationalize near-unity anti-Stokes photoluminescence efficiencies in CsPbBr3 nanocrystals and attribute them to resonant multiple-phonon absorption by polarons. The theory explains paradoxically large efficiencies for intrinsically disfavored, multiple-phonon-assisted ASPL in nanocrystals. Moreover, the developed microscopic mechanism has immediate and important implications for applications of ASPL toward condensed phase optical refrigeration.
Original language | English (US) |
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Pages (from-to) | 6438-6444 |
Number of pages | 7 |
Journal | ACS nano |
Volume | 18 |
Issue number | 8 |
DOIs | |
State | Published - Feb 27 2024 |
Funding
This work is dedicated to the memory of Mansoor Sheik-Bahae. We thank the MURI:MARBLe project under the auspices of the Air Force Office of Scientific Research (Award No. FA9550-16-1-0362) for financial support. This work was also supported, in part, by the National Science Foundation under award DMR-1952841. M.B. acknowledges support from the Max Planck-UBC-UTokyo Center for Quantum Materials and Canada First Research Excellence Fund (CFREF) Quantum Materials and Future Technologies Program of the Stewart Blusson Quantum Matter Institute and the Natural Sciences and Engineering Research Council of Canada. Work performed at the Center for Nanoscale Materials, a U.S. Department of Energy Office of Science User Facility, was supported by the U.S. DOE, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357
Keywords
- anti-Stokes photoluminescence
- lead halide perovskite
- nanocrystal
- optical refrigeration
- photoluminescence
- polaron
- up-conversion photoluminescence
ASJC Scopus subject areas
- General Materials Science
- General Engineering
- General Physics and Astronomy