Confinement and Exciton Binding Energy Effects on Hot Carrier Cooling in Lead Halide Perovskite Nanomaterials


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Date

2023-04-11

Publication Type

Journal Article

ETH Bibliography

yes

Citations

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Data

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.

Publication status

published

Editor

Book title

Journal / series

Volume

17 (7)

Pages / Article No.

6638 - 6648

Publisher

American Chemical Society

Event

Edition / version

Methods

Software

Geographic location

Date collected

Date created

Subject

hot carriers; two-dimensional perovskites; nanoplatelets; nanocrystals; ultrafast spectroscopy

Organisational unit

03934 - Kovalenko, Maksym / Kovalenko, Maksym check_circle

Notes

Funding

899141 - Polariton logic (EC)

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