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Confinement and Exciton Binding Energy Effects on Hot Carrier Cooling in Lead Halide Perovskite Nanomaterials.
- Source :
-
ACS nano [ACS Nano] 2023 Apr 11; Vol. 17 (7), pp. 6638-6648. Date of Electronic Publication: 2023 Mar 20. - Publication Year :
- 2023
-
Abstract
- The relaxation of the above-gap ("hot") carriers in lead halide perovskites (LHPs) is important for applications in photovoltaics and offers insights into carrier-carrier and carrier-phonon interactions. However, the role of quantum confinement in the hot carrier dynamics of nanosystems is still disputed. Here, we devise a single approach, ultrafast pump-push-probe spectroscopy, to study carrier cooling in six different size-controlled LHP nanomaterials. In cuboidal nanocrystals, we observe only a weak size effect on the cooling dynamics. In contrast, two-dimensional systems show suppression of the hot phonon bottleneck effect common in bulk perovskites. The proposed kinetic model describes the intrinsic and density-dependent cooling times accurately in all studied perovskite systems using only carrier-carrier, carrier-phonon, and excitonic coupling constants. This highlights the impact of exciton formation on carrier cooling and promotes dimensional confinement as a tool for engineering carrier-phonon and carrier-carrier interactions in LHP optoelectronic materials.
Details
- Language :
- English
- ISSN :
- 1936-086X
- Volume :
- 17
- Issue :
- 7
- Database :
- MEDLINE
- Journal :
- ACS nano
- Publication Type :
- Academic Journal
- Accession number :
- 36939330
- Full Text :
- https://doi.org/10.1021/acsnano.2c12373