Enhancing the Photoexcited Carrier Spin Relaxation Lifetime in CsPbBr<sub>3</sub> Perovskite Quantum Dots by <sup>208</sup>Pb Isotope Enrichment
CsPbBr<sub>3</sub> perovskite quantum dot (PQD) films enriched with <sup>208</sup>Pb (<i>I</i> = 0) or <sup>207</sup>Pb (<i>I</i> = 1/2) isotope were used to study the effect of nuclear spin on the photoexcited carrier spin relaxation using circularly polarized femtosecond transient absorption spectroscopy at 293 and 77 K. At 293 K, the short carrier spin relaxation lifetimes of <sup>208</sup>Pb-enriched PQDs (2.0 ps) and <sup>nat</sup>Pb PQDs (0.70 ps) indicate that electron-phonon interactions dominate. At 77 K, the <sup>207</sup>Pb-enriched PQD carrier spin relaxation lifetime was not detectible within the instrumental limit (<0.30 ps). However, the carrier spin relaxation lifetime increased to 5.0 ps for <sup>nat</sup>Pb PQDs and 170 ps for <sup>208</sup>Pb-enriched PQDs. The dramatic increase in the <sup>208</sup>Pb-enriched PQD carrier spin relaxation lifetime suggests that decreasing the concentration of <sup>207</sup>Pb in the PQDs can reduce spin decoherence from nuclear spin-carrier spin coupling and enhance the lifetime.
Authors
- Jason K. Cooper (ORCID: https://orcid.org/0000-0002-7953-4229)
- David C. Zeitz (ORCID: https://orcid.org/0009-0006-0473-1849)
- Jin Z. Zhang (ORCID: https://orcid.org/0000-0003-3437-912X)
- Yuan Ping (ORCID: https://orcid.org/0000-0002-0123-3389)
- Vivien L. Cherrette
- Mariam Khvichia
Institutions
- nLIGHT (United States) (US)
- University of Wisconsin–Madison (US)
- Lawrence Berkeley National Laboratory (US)
- University of California, Santa Cruz (US)
- Digital Research Alliance of Canada
Publication Details
- Journal
- The Journal of Physical Chemistry Letters
- Published
- 2025-03-25
- DOI
- https://doi.org/10.1021/acs.jpclett.5c00123
- Citations
- 2
- Primary Topic
- Perovskite Materials and Applications
- Type
- article
- Field-Weighted Citation Impact
- 1.46
Funders
- Division of Chemistry
- Basic Energy Sciences