Enhanced Emission from Bright Excitons in Asymmetrically Strained Colloidal CdSe/CdxZn1- xSe Quantum Dots

Igor Fedin, Mateusz Goryca, Dan Liu, Sergei Tretiak, Victor I. Klimov, Scott A. Crooker

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

Colloidal CdSe quantum dots (QDs) designed with a high degree of asymmetric internal strain have recently been shown to host a number of desirable optical properties including subthermal room-temperature line widths, suppressed spectral diffusion, and high photoluminescence (PL) quantum yields. It remains an open question, however, whether they are well-suited for applications requiring emission of identical single photons. Here we measure the low-temperature PL dynamics and the polarization-resolved fluorescence line narrowing spectra from ensembles of these strained QDs. Our spectroscopy reveals the radiative recombination rates of bright and dark excitons, the relaxation rate between the two, and the energy spectra of the quantized acoustic phonons in the QDs that can contribute to relaxation processes. In comparison to conventional colloidal CdSe/ZnS core/shell QDs, we find that in asymmetrically strained CdSe QDs over six times more light is emitted directly by the bright exciton. These results are therefore encouraging for the prospects of chemically synthesized colloidal QDs as emitters of single indistinguishable photons.

Original languageEnglish
Pages (from-to)14444-14452
JournalACS Nano
Volume15
Issue number9
DOIs
Publication statusPublished - 2021
Externally publishedYes

Keywords

  • acoustic phonon
  • bright exciton
  • colloidal quantum dot
  • exciton fine structure
  • nanocrystal
  • single-photon emitter

Fingerprint

Dive into the research topics of 'Enhanced Emission from Bright Excitons in Asymmetrically Strained Colloidal CdSe/CdxZn1- xSe Quantum Dots'. Together they form a unique fingerprint.

Cite this