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Title: Carrier Dynamics and Interactions for Bulklike Photoexcitation of Colloidal Indium Arsenide Quantum Dots

Journal Article · · Journal of Physical Chemistry. C

The remarkable photonic and photochemical properties of colloidal quantum dots (QD) depend critically on the dynamics of carrier interactions and relaxation. Despite their importance, a quantitative experimental evaluation of these processes has proven elusive due to the inherent challenge of exactly separating singleexciton and multiexciton dynamics, whose spectroscopic signatures overlap in time, spectrum, and excitation fluence. Here, we measure pump-fluence-dependent absolute pump-probe transients of indium arsenide QDs, refreshing the sample using beam scanning to limit repetitive excitation. Focusing on the low fluence limit near the onset of biexciton formation, excitation conditions were precisely controlled and characterized by averaging Poisson-distributed excitation statistics over all three spatial dimensions of the pump and probe beam spatial profiles to determine the average excitation probability. A saturation model is developed to uniquely decompose the pump-probe signal into singleexciton and biexciton signals. This method harnesses the distinct pump-fluence scaling of absolute pump-probe signals from singly and doubly excited QDs without any assumptions regarding the relative time scales or amplitudes of single-exciton and biexciton signals. Probing in the bulklike region of the QD absorption spectrum, the signal from biexcitons is found to be 1.8 times the signal from single excitons at T = 0, consistent with the conventionally assumed factor of 2 within the 95% confidence intervals. The biexciton signal contains the same hot-carrier relaxation dynamics as that from single excitons, but signal from a second exciton additionally exhibits a 26 ps exponential decay attributed to Auger recombination.

Research Organization:
National Renewable Energy Laboratory (NREL), Golden, CO (United States); Northwestern Univ., Evanston, IL (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences, and Biosciences Division
Grant/Contract Number:
FG02-07ER15912; AC36-08GO28308
OSTI ID:
1490564
Alternate ID(s):
OSTI ID: 1494738; OSTI ID: 1508806
Report Number(s):
NREL/JA-5900-71919
Journal Information:
Journal of Physical Chemistry. C, Journal Name: Journal of Physical Chemistry. C Vol. 123 Journal Issue: 1; ISSN 1932-7447
Publisher:
American Chemical SocietyCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 3 works
Citation information provided by
Web of Science

References (36)

Carrier Multiplication in InAs Nanocrystal Quantum Dots with an Onset Defined by the Energy Conservation Limit journal November 2007
High Efficiency Carrier Multiplication in PbSe Nanocrystals: Implications for Solar Energy Conversion journal May 2004
Absorption Cross-Section and Related Optical Properties of Colloidal InAs Quantum Dots journal April 2005
Origin and control of blinking in quantum dots journal August 2016
On the Absence of Detectable Carrier Multiplication in a Transient Absorption Study of InAs/CdSe/ZnSe Core/Shell1/Shell2 Quantum Dots journal April 2008
Heterogeneity of the Electron-Trapping Kinetics in CdSe Nanoparticles journal August 2011
Emergence of colloidal quantum-dot light-emitting technologies journal December 2012
Bulklike Hot Carrier Dynamics in Lead Sulfide Quantum Dots journal July 2010
Apparent Versus True Carrier Multiplication Yields in Semiconductor Nanocrystals journal June 2010
Carrier Multiplication and Its Reduction by Photodoping in Colloidal InAs Quantum Dots journal March 2008
Spectral Dependence of Nanocrystal Photoionization Probability: The Role of Hot-Carrier Transfer journal May 2011
Quantization of Multiparticle Auger Rates in Semiconductor Quantum Dots journal February 2000
Kinetics of II-VI and III-V Colloidal Semiconductor Nanocrystal Growth:  “Focusing” of Size Distributions journal June 1998
Characterization of the Ligand Capping of Hydrophobic CdSe–ZnS Quantum Dots Using NMR Spectroscopy journal December 2017
Multiple exciton generation in semiconductor quantum dots journal May 2008
Quantum dots versus organic dyes as fluorescent labels journal August 2008
Sample exchange by beam scanning with applications to noncollinear pump–probe spectroscopy at kilohertz repetition rates journal June 2017
Theory of Avalanche Breakdown in InSb and InAs journal March 1968
Enhanced Polar Exciton-LO-Phonon Interaction in Quantum Dots journal November 1999
Interferometrically stable, enclosed, spinning sample cell for spectroscopic experiments on air-sensitive samples journal January 2017
White-Light-Emitting Diodes with Quantum Dot Color Converters for Display Backlights journal May 2010
Challenge to the Charging Model of Semiconductor-Nanocrystal Fluorescence Intermittency from Off-State Quantum Yields and Multiexciton Blinking journal April 2010
Growth and Properties of Semiconductor Core/Shell Nanocrystals with InAs Cores journal October 2000
Flowing versus Static Conditions for Measuring Multiple Exciton Generation in PbSe Quantum Dots journal September 2010
Raman scattering by plasmon-phonon modes in highly doped n-InAs grown by molecular beam epitaxy journal September 1992
(Multi)exciton Dynamics and Exciton Polarizability in Colloidal InAs Quantum Dots journal March 2010
Band parameters for III–V compound semiconductors and their alloys journal June 2001
Water-Soluble Quantum Dots for Multiphoton Fluorescence Imaging in Vivo journal May 2003
Excited-State Dynamics in Colloidal Semiconductor Nanocrystals journal August 2016
Carrier Multiplication and Its Reduction by Photodoping in Colloidal InAs Quantum Dots journal February 2007
Accurate band structures and effective masses for InP, InAs, and InSb using hybrid functionals journal July 2009
Single Photon Counting from Individual Nanocrystals in the Infrared journal May 2012
Electron impact ionization in semiconductors journal January 1959
Quantum dot solar cells journal April 2002
Size-dependent dynamics of coherent acoustic phonons in nanocrystal quantum dots journal July 1999
Nanocrystalline TiO 2 Solar Cells Sensitized with InAs Quantum Dots journal December 2006