We've updated our Privacy Policy to make it clearer how we use your personal data.

We use cookies to provide you with a better experience. You can read our Cookie Policy here.

Femtosecond Spectroscopy Sheds Light on Promising Materials

Femtosecond Spectroscopy Sheds Light on Promising Materials

Femtosecond Spectroscopy Sheds Light on Promising Materials

Femtosecond Spectroscopy Sheds Light on Promising Materials

Credit: Pixabay.
Read time:

Want a FREE PDF version of This News Story?

Complete the form below and we will email you a PDF version of "Femtosecond Spectroscopy Sheds Light on Promising Materials"

First Name*
Last Name*
Email Address*
Company Type*
Job Function*
Would you like to receive further email communication from Technology Networks?

Technology Networks Ltd. needs the contact information you provide to us to contact you about our products and services. You may unsubscribe from these communications at any time. For information on how to unsubscribe, as well as our privacy practices and commitment to protecting your privacy, check out our Privacy Policy

Researchers from Skoltech and Ludwig Maximilians-Universität (LMU) in Germany have studied the fundamental properties of halide perovskite nanocrystals, a promising class of optoelectronic materials. Using a combination of theory and experiment, they were able to show and explain an intricate connection between composition, light-induced lattice dynamics, and stability of the materials. The paper was published in the journal Nature Communications.

Perovskite nanocrystals (PNCs) are semiconductor nanocrystals that, thanks to their unique properties, have found a number of applications in optoelectronics, for instance, in lasers and LEDs. PNCs have a much higher photoluminescence quantum yield compared to bulk materials. Moreover, at nanoscale the quantum-confinement can be achieved, which could be used as an additional means of tuning optical properties of such materials. Metal halide perovskites have electronic properties that make the optical properties of nanocrystals made from these materials more tolerant to defects than other semiconducting materials.

Assistant Professor at the Skoltech Center for Energy Science and Technology (CEST) Sergey Levchenko and his colleagues used atomistic modelling to explain the results of femtosecond pump-probe spectroscopy, a method that allows to observe lattice dynamics in real time. They studied the coherent lattice vibrational dynamics - how atomic structure of PNCs evolves after excitation with a laser pulse with a duration shorter than the period of vibrational modes -- for hybrid halide PNCs.

They found, among other things, that energy transfer between vibrational modes in iodine-based perovskite nanocrystals is much more pronounced than in bromine-based ones due to a difference in interaction between the inorganic framework and the organic moiety in organic-inorganic halide PNCs.

"These results pave the way to a rational control over fundamental properties of such PNCs, including energy transfer upon optical excitation and charge-carrier relaxation, via compositional changes," Levchenko says.

Debnath T et al. Coherent vibrational dynamics reveals lattice anharmonicity in organic–inorganic halide perovskite nanocrystals. Nat Commun 12, 2629 (2021). https://doi.org/10.1038/s41467-021-22934-2

This article has been republished from the following materials. Note: material may have been edited for length and content. For further information, please contact the cited source.