Higher-Order Photon Correlation as a Tool to Study Exciton Dynamics in Quasi-2D Nanoplatelets

Daniel Amgar, Gaoling Yang, Ron Tenne, Dan Oron

Research output: Contribution to journalArticle

Abstract

Colloidal semiconductor nanoplatelets, in which carriers are strongly confined only along one dimension, present fundamentally different excitonic properties than quantum dots, which support strong confinement in all three dimensions. In particular, multiple excitons strongly confined in just one dimension are free to rearrange in the lateral plane, reducing the probability for multibody collisions. Thus, while simultaneous multiple photon emission is typically quenched in quantum dots, in nanoplatelets its probability can be tuned according to size and shape. Here, we focus on analyzing multiexciton dynamics in individual CdSe/CdS nanoplatelets of various sizes through the measurement of second-, third-, and fourth-order photon correlations. For the first time, we can directly probe the dynamics of the two, three, and four exciton states at the single nanocrystal level. Remarkably, although higher orders of correlation vary substantially among the synthesis' products, they strongly correlate with the value of second order antibunching. The scaling of the higher-order moments with the degree of antibunching presents a small yet clear deviation from the accepted model of Auger recombination through binary collisions. Such a deviation suggests that many-body contributions are present already at the level of triexcitons. These findings highlight the benefit of high-order photon correlation spectroscopy as a technique to study multiexciton dynamics in colloidal semiconductor nanocrystals.

Original languageEnglish
JournalNano letters
DOIs
Publication statusAccepted/In press - Jan 1 2019

Fingerprint

Excitons
Photons
excitons
Nanocrystals
Semiconductor quantum dots
nanocrystals
photons
quantum dots
Semiconductor materials
Photon correlation spectroscopy
deviation
collisions
moments
scaling
probes
synthesis
products
spectroscopy
LDS 751

Keywords

  • Auger recombination
  • exciton dynamics
  • multiexcitons
  • nanoplatelets
  • photon correlation

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

Cite this

Higher-Order Photon Correlation as a Tool to Study Exciton Dynamics in Quasi-2D Nanoplatelets. / Amgar, Daniel; Yang, Gaoling; Tenne, Ron; Oron, Dan.

In: Nano letters, 01.01.2019.

Research output: Contribution to journalArticle

@article{d99d255989bb42f7b32bbdbbbfbe6520,
title = "Higher-Order Photon Correlation as a Tool to Study Exciton Dynamics in Quasi-2D Nanoplatelets",
abstract = "Colloidal semiconductor nanoplatelets, in which carriers are strongly confined only along one dimension, present fundamentally different excitonic properties than quantum dots, which support strong confinement in all three dimensions. In particular, multiple excitons strongly confined in just one dimension are free to rearrange in the lateral plane, reducing the probability for multibody collisions. Thus, while simultaneous multiple photon emission is typically quenched in quantum dots, in nanoplatelets its probability can be tuned according to size and shape. Here, we focus on analyzing multiexciton dynamics in individual CdSe/CdS nanoplatelets of various sizes through the measurement of second-, third-, and fourth-order photon correlations. For the first time, we can directly probe the dynamics of the two, three, and four exciton states at the single nanocrystal level. Remarkably, although higher orders of correlation vary substantially among the synthesis' products, they strongly correlate with the value of second order antibunching. The scaling of the higher-order moments with the degree of antibunching presents a small yet clear deviation from the accepted model of Auger recombination through binary collisions. Such a deviation suggests that many-body contributions are present already at the level of triexcitons. These findings highlight the benefit of high-order photon correlation spectroscopy as a technique to study multiexciton dynamics in colloidal semiconductor nanocrystals.",
keywords = "Auger recombination, exciton dynamics, multiexcitons, nanoplatelets, photon correlation",
author = "Daniel Amgar and Gaoling Yang and Ron Tenne and Dan Oron",
year = "2019",
month = "1",
day = "1",
doi = "10.1021/acs.nanolett.9b03442",
language = "English",
journal = "Nano Letters",
issn = "1530-6984",
publisher = "American Chemical Society",

}

TY - JOUR

T1 - Higher-Order Photon Correlation as a Tool to Study Exciton Dynamics in Quasi-2D Nanoplatelets

AU - Amgar, Daniel

AU - Yang, Gaoling

AU - Tenne, Ron

AU - Oron, Dan

PY - 2019/1/1

Y1 - 2019/1/1

N2 - Colloidal semiconductor nanoplatelets, in which carriers are strongly confined only along one dimension, present fundamentally different excitonic properties than quantum dots, which support strong confinement in all three dimensions. In particular, multiple excitons strongly confined in just one dimension are free to rearrange in the lateral plane, reducing the probability for multibody collisions. Thus, while simultaneous multiple photon emission is typically quenched in quantum dots, in nanoplatelets its probability can be tuned according to size and shape. Here, we focus on analyzing multiexciton dynamics in individual CdSe/CdS nanoplatelets of various sizes through the measurement of second-, third-, and fourth-order photon correlations. For the first time, we can directly probe the dynamics of the two, three, and four exciton states at the single nanocrystal level. Remarkably, although higher orders of correlation vary substantially among the synthesis' products, they strongly correlate with the value of second order antibunching. The scaling of the higher-order moments with the degree of antibunching presents a small yet clear deviation from the accepted model of Auger recombination through binary collisions. Such a deviation suggests that many-body contributions are present already at the level of triexcitons. These findings highlight the benefit of high-order photon correlation spectroscopy as a technique to study multiexciton dynamics in colloidal semiconductor nanocrystals.

AB - Colloidal semiconductor nanoplatelets, in which carriers are strongly confined only along one dimension, present fundamentally different excitonic properties than quantum dots, which support strong confinement in all three dimensions. In particular, multiple excitons strongly confined in just one dimension are free to rearrange in the lateral plane, reducing the probability for multibody collisions. Thus, while simultaneous multiple photon emission is typically quenched in quantum dots, in nanoplatelets its probability can be tuned according to size and shape. Here, we focus on analyzing multiexciton dynamics in individual CdSe/CdS nanoplatelets of various sizes through the measurement of second-, third-, and fourth-order photon correlations. For the first time, we can directly probe the dynamics of the two, three, and four exciton states at the single nanocrystal level. Remarkably, although higher orders of correlation vary substantially among the synthesis' products, they strongly correlate with the value of second order antibunching. The scaling of the higher-order moments with the degree of antibunching presents a small yet clear deviation from the accepted model of Auger recombination through binary collisions. Such a deviation suggests that many-body contributions are present already at the level of triexcitons. These findings highlight the benefit of high-order photon correlation spectroscopy as a technique to study multiexciton dynamics in colloidal semiconductor nanocrystals.

KW - Auger recombination

KW - exciton dynamics

KW - multiexcitons

KW - nanoplatelets

KW - photon correlation

UR - http://www.scopus.com/inward/record.url?scp=85075657627&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85075657627&partnerID=8YFLogxK

U2 - 10.1021/acs.nanolett.9b03442

DO - 10.1021/acs.nanolett.9b03442

M3 - Article

C2 - 31692360

AN - SCOPUS:85075657627

JO - Nano Letters

JF - Nano Letters

SN - 1530-6984

ER -