Effect of Auger Recombination on Lasing in Heterostructured Quantum Dots with Engineered Core/Shell Interfaces

Young Shin Park, Wan Ki Bae, Thomas Baker, Jaehoon Lim, Victor I Klimov

Research output: Contribution to journalArticle

67 Citations (Scopus)

Abstract

Nanocrystal quantum dots (QDs) are attractive materials for applications as laser media because of their bright, size-tunable emission and the flexibility afforded by colloidal synthesis. Nonradiative Auger recombination, however, hampers optical amplification in QDs by rapidly depleting the population of gain-active multiexciton states. In order to elucidate the role of Auger recombination in QD lasing and isolate its influence from other factors that might affect optical gain, we study two types of CdSe/CdS core/shell QDs with the same core radii and the same total sizes but different properties of the core/shell interface ("sharp" vs "smooth"). These samples exhibit distinctly different biexciton Auger lifetimes but are otherwise virtually identical. The suppression of Auger recombination in the sample with a smooth (alloyed) interface results in a notable improvement in the optical gain performance manifested in the reduction of the threshold for amplified spontaneous emission and the ability to produce dual-color lasing involving both the band-edge (1S) and the higher-energy (1P) electronic states. We develop a model, which explicitly accounts for the multiexciton nature of optical gain in QDs, and use it to analyze the competition between stimulated emission from multiexcitons and their decay via Auger recombination. These studies re-emphasize the importance of Auger recombination control for the realization of real-life QD-based lasing technologies and offer practical strategies for suppression of Auger recombination via "interface engineering" in core/shell structures.

Original languageEnglish
Pages (from-to)7319-7328
Number of pages10
JournalNano Letters
Volume15
Issue number11
DOIs
Publication statusPublished - Nov 11 2015

Fingerprint

Semiconductor quantum dots
lasing
quantum dots
Optical gain
retarding
Stimulated emission
Spontaneous emission
Electronic states
stimulated emission
Nanocrystals
spontaneous emission
Amplification
nanocrystals
flexibility
engineering
Color
color
life (durability)
radii
thresholds

Keywords

  • Auger recombination
  • core/shell heterostructure
  • lasing
  • optical gain
  • quantum dot
  • semiconductor nanocrystal

ASJC Scopus subject areas

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

Cite this

Effect of Auger Recombination on Lasing in Heterostructured Quantum Dots with Engineered Core/Shell Interfaces. / Park, Young Shin; Bae, Wan Ki; Baker, Thomas; Lim, Jaehoon; Klimov, Victor I.

In: Nano Letters, Vol. 15, No. 11, 11.11.2015, p. 7319-7328.

Research output: Contribution to journalArticle

Park, Young Shin ; Bae, Wan Ki ; Baker, Thomas ; Lim, Jaehoon ; Klimov, Victor I. / Effect of Auger Recombination on Lasing in Heterostructured Quantum Dots with Engineered Core/Shell Interfaces. In: Nano Letters. 2015 ; Vol. 15, No. 11. pp. 7319-7328.
@article{5d717a9a8c074d2bb5a3f99a685c61f8,
title = "Effect of Auger Recombination on Lasing in Heterostructured Quantum Dots with Engineered Core/Shell Interfaces",
abstract = "Nanocrystal quantum dots (QDs) are attractive materials for applications as laser media because of their bright, size-tunable emission and the flexibility afforded by colloidal synthesis. Nonradiative Auger recombination, however, hampers optical amplification in QDs by rapidly depleting the population of gain-active multiexciton states. In order to elucidate the role of Auger recombination in QD lasing and isolate its influence from other factors that might affect optical gain, we study two types of CdSe/CdS core/shell QDs with the same core radii and the same total sizes but different properties of the core/shell interface ({"}sharp{"} vs {"}smooth{"}). These samples exhibit distinctly different biexciton Auger lifetimes but are otherwise virtually identical. The suppression of Auger recombination in the sample with a smooth (alloyed) interface results in a notable improvement in the optical gain performance manifested in the reduction of the threshold for amplified spontaneous emission and the ability to produce dual-color lasing involving both the band-edge (1S) and the higher-energy (1P) electronic states. We develop a model, which explicitly accounts for the multiexciton nature of optical gain in QDs, and use it to analyze the competition between stimulated emission from multiexcitons and their decay via Auger recombination. These studies re-emphasize the importance of Auger recombination control for the realization of real-life QD-based lasing technologies and offer practical strategies for suppression of Auger recombination via {"}interface engineering{"} in core/shell structures.",
keywords = "Auger recombination, core/shell heterostructure, lasing, optical gain, quantum dot, semiconductor nanocrystal",
author = "Park, {Young Shin} and Bae, {Wan Ki} and Thomas Baker and Jaehoon Lim and Klimov, {Victor I}",
year = "2015",
month = "11",
day = "11",
doi = "10.1021/acs.nanolett.5b02595",
language = "English",
volume = "15",
pages = "7319--7328",
journal = "Nano Letters",
issn = "1530-6984",
publisher = "American Chemical Society",
number = "11",

}

TY - JOUR

T1 - Effect of Auger Recombination on Lasing in Heterostructured Quantum Dots with Engineered Core/Shell Interfaces

AU - Park, Young Shin

AU - Bae, Wan Ki

AU - Baker, Thomas

AU - Lim, Jaehoon

AU - Klimov, Victor I

PY - 2015/11/11

Y1 - 2015/11/11

N2 - Nanocrystal quantum dots (QDs) are attractive materials for applications as laser media because of their bright, size-tunable emission and the flexibility afforded by colloidal synthesis. Nonradiative Auger recombination, however, hampers optical amplification in QDs by rapidly depleting the population of gain-active multiexciton states. In order to elucidate the role of Auger recombination in QD lasing and isolate its influence from other factors that might affect optical gain, we study two types of CdSe/CdS core/shell QDs with the same core radii and the same total sizes but different properties of the core/shell interface ("sharp" vs "smooth"). These samples exhibit distinctly different biexciton Auger lifetimes but are otherwise virtually identical. The suppression of Auger recombination in the sample with a smooth (alloyed) interface results in a notable improvement in the optical gain performance manifested in the reduction of the threshold for amplified spontaneous emission and the ability to produce dual-color lasing involving both the band-edge (1S) and the higher-energy (1P) electronic states. We develop a model, which explicitly accounts for the multiexciton nature of optical gain in QDs, and use it to analyze the competition between stimulated emission from multiexcitons and their decay via Auger recombination. These studies re-emphasize the importance of Auger recombination control for the realization of real-life QD-based lasing technologies and offer practical strategies for suppression of Auger recombination via "interface engineering" in core/shell structures.

AB - Nanocrystal quantum dots (QDs) are attractive materials for applications as laser media because of their bright, size-tunable emission and the flexibility afforded by colloidal synthesis. Nonradiative Auger recombination, however, hampers optical amplification in QDs by rapidly depleting the population of gain-active multiexciton states. In order to elucidate the role of Auger recombination in QD lasing and isolate its influence from other factors that might affect optical gain, we study two types of CdSe/CdS core/shell QDs with the same core radii and the same total sizes but different properties of the core/shell interface ("sharp" vs "smooth"). These samples exhibit distinctly different biexciton Auger lifetimes but are otherwise virtually identical. The suppression of Auger recombination in the sample with a smooth (alloyed) interface results in a notable improvement in the optical gain performance manifested in the reduction of the threshold for amplified spontaneous emission and the ability to produce dual-color lasing involving both the band-edge (1S) and the higher-energy (1P) electronic states. We develop a model, which explicitly accounts for the multiexciton nature of optical gain in QDs, and use it to analyze the competition between stimulated emission from multiexcitons and their decay via Auger recombination. These studies re-emphasize the importance of Auger recombination control for the realization of real-life QD-based lasing technologies and offer practical strategies for suppression of Auger recombination via "interface engineering" in core/shell structures.

KW - Auger recombination

KW - core/shell heterostructure

KW - lasing

KW - optical gain

KW - quantum dot

KW - semiconductor nanocrystal

UR - http://www.scopus.com/inward/record.url?scp=84946924464&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84946924464&partnerID=8YFLogxK

U2 - 10.1021/acs.nanolett.5b02595

DO - 10.1021/acs.nanolett.5b02595

M3 - Article

VL - 15

SP - 7319

EP - 7328

JO - Nano Letters

JF - Nano Letters

SN - 1530-6984

IS - 11

ER -