Internal Electric Field Manipulates Exciton–Phonon Couplings in Single Lead Halide Perovskite Nanocrystals

Authors:
Publisher website
Google Scholar
Abstract
Lead halide perovskite nanocrystals (NCs) have attracted much attention as materials for light-emitting diodes and quantum light sources. A deep understanding of exciton-phonon couplings is essential for obtaining a narrow emission line, weak phonon-sideband photoluminescence (PL), and a long exciton coherence time, which are especially useful for high-color-purity quantum-light-source applications. Here, we report the PL spectra of single CsPbBr3 NCs at 5.5 K as a function of the applied electric field. The exciton peak energy shows an asymmetric parabolic shift for positive and negative biases, implying the presence of a spontaneously generated internal electric field in the NCs when no field is applied. Both the internal electric field and exciton-phonon couplings become larger in smaller NCs, and they have a positive correlation with each other. Our findings show that the exciton-phonon couplings can be manipulated with an electric field, which dominates the PL properties of perovskite NCs.
Funding Information
  • Core Research for Evolutional Science and Technology (JPMJCR21B4)
  • Precursory Research for Embryonic Science and Technology (JPMJPR23H3)
  • Japan Society for the Promotion of Science (JP19H05465, JP23K17877, JP23K23258, JP23KJ1291)

This publication has 73 references indexed in Scilit: