Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.



Probing lattice vibrations of stabilized CsPbI3 polymorphs via low-frequency Raman spectroscopy

Author affiliations

Abstract

Understanding electron–phonon interactions in metal-halide perovskites (MHPs) is critical for improving their performance in optoelectronic devices. Probing lattice vibrations with conventional spectroscopic methods, however, is challenging due to the sensitivity of MHPs to laser light, humidity, and temperature changes. Here we report low-frequency Raman spectra of the δ and γ phases, as well as mixed ion derivatives, of CsPbI3. These spectra were obtained by combining below-bandgap low-frequency Raman measurements using a 976 nm laser and nanoconfinement of crystals within inert scaffolds to stabilize the MHPs against temperature-induced polymorph transitions and humidity-induced degradation. Density functional theory calculations demonstrate that the main vibrational modes in the δ- and γ-CsPbI3 Raman spectra correspond to octahedral twisting and distortions. Effects of the A-site cation and halide on these vibrational modes were determined by analyzing low-frequency Raman spectra of CsPbIxBr3−x and MAyCs1−yPbI3. The Raman peak positions primarily depend on the lattice dimensions, regardless of the nature of the cations and anions, with lattice expansions causing a shift of the vibrational modes to lower frequencies.

Graphical abstract: Probing lattice vibrations of stabilized CsPbI3 polymorphs via low-frequency Raman spectroscopy

Back to tab navigation

Supplementary files

Article information


Submitted
30 Apr 2020
Accepted
03 Jun 2020
First published
03 Jun 2020

J. Mater. Chem. C, 2020, Advance Article
Article type
Paper

Probing lattice vibrations of stabilized CsPbI3 polymorphs via low-frequency Raman spectroscopy

Y. Yang, J. P. Robbins, L. Ezeonu, Y. Ma, N. Sparta, X. Kong, S. Strauf, S. G. Podkolzin and S. S. Lee, J. Mater. Chem. C, 2020, Advance Article , DOI: 10.1039/D0TC02123G

Social activity

Search articles by author

Spotlight

Advertisements