Research output: Contribution to journal › Article › peer-review
Confined Acoustic Phonons in CsPbI3 Nanocrystals Explored by Resonant Raman Scattering on Excitons. / Harkort, Carolin; Kalitukha, I. V.; Коптева, Наталия Евгеньевна; Nestoklon, Mikhail; Goupalov, Serguei; Saviot, Lucien; Kudlachik, Dennis; Yakovlev, Dmitri R.; Колобкова, Елена; Кузнецова, Мария Сергеевна; Bayer, Manfred.
In: Nano Letters, Vol. 25, No. 33, 07.08.2025, p. 12754-12761.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Confined Acoustic Phonons in CsPbI3 Nanocrystals Explored by Resonant Raman Scattering on Excitons
AU - Harkort, Carolin
AU - Kalitukha, I. V.
AU - Коптева, Наталия Евгеньевна
AU - Nestoklon, Mikhail
AU - Goupalov, Serguei
AU - Saviot, Lucien
AU - Kudlachik, Dennis
AU - Yakovlev, Dmitri R.
AU - Колобкова, Елена
AU - Кузнецова, Мария Сергеевна
AU - Bayer, Manfred
PY - 2025/8/7
Y1 - 2025/8/7
N2 - Optical properties of the lead halide perovskite nanocrystals are controlled by confined excitons and a rich spectrum of confined acoustic and optical phonons. We study experimentally and theoretically the exciton-phonon interaction in CsPbI3 perovskite nanocrystals embedded in a glass matrix. Energies of phonon modes allowed by selection rules are detected by resonant Raman scattering for nanocrystals with sizes of 4-13 nm, covering exciton energies of 1.72-2.25 eV. While optical phonon energies remain size-independent, the energies of confined acoustic phonons increase in smaller nanocrystals. Acoustic phonons are modeled within the continuum approximation by using elastic constants computed by density functional theory. The model provides the energy spectra of confined phonons for nanocrystals with cubic, spherical, and spheroidal shapes, orthorhombic and tetragonal symmetries, and different sizes. Exciton confinement restricts efficient coupling to a few phonon modes observable in Raman spectra. By comparing experimental data with model predictions, we conclude that the nanocrystals predominantly have spherical or spheroidal shapes.
AB - Optical properties of the lead halide perovskite nanocrystals are controlled by confined excitons and a rich spectrum of confined acoustic and optical phonons. We study experimentally and theoretically the exciton-phonon interaction in CsPbI3 perovskite nanocrystals embedded in a glass matrix. Energies of phonon modes allowed by selection rules are detected by resonant Raman scattering for nanocrystals with sizes of 4-13 nm, covering exciton energies of 1.72-2.25 eV. While optical phonon energies remain size-independent, the energies of confined acoustic phonons increase in smaller nanocrystals. Acoustic phonons are modeled within the continuum approximation by using elastic constants computed by density functional theory. The model provides the energy spectra of confined phonons for nanocrystals with cubic, spherical, and spheroidal shapes, orthorhombic and tetragonal symmetries, and different sizes. Exciton confinement restricts efficient coupling to a few phonon modes observable in Raman spectra. By comparing experimental data with model predictions, we conclude that the nanocrystals predominantly have spherical or spheroidal shapes.
KW - confined acoustic phonons
KW - elastic constants
KW - optical phonons
KW - perovskite nanocrystals
KW - resonant Raman scattering
UR - https://www.mendeley.com/catalogue/d4319680-a53e-35f1-ad3e-fdc2760fffad/
U2 - 10.1021/acs.nanolett.5c03342
DO - 10.1021/acs.nanolett.5c03342
M3 - Article
VL - 25
SP - 12754
EP - 12761
JO - Nano Letters
JF - Nano Letters
SN - 1530-6984
IS - 33
ER -
ID: 140463605