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Title: Understanding and Curing Structural Defects in Colloidal GaAs Nanocrystals

Abstract

Nearly three decades since the first report on the synthesis of colloidal GaAs nanocrystals (NCs), the preparation and properties of this material remain highly controversial. Traditional synthetic routes either fail to produce the GaAs phase or result in materials that do not show expected optical properties such as excitonic transitions. In this work, we demonstrate a variety of synthetic routes toward crystalline GaAs NCs. By using a combination of Raman, EXAFS and transient absorption spectroscopies, we conclude that unusual optical properties of 2 colloidal GaAs NCs can be related to the presence of vacancies and lattice disorder. We introduce novel molten salt based annealing approach to alleviate these structural defects and show the emergence of size-dependent excitonic transitions in colloidal GaAs quantum dots.

Authors:
 [1];  [1];  [1];  [1];  [1];  [2]; ORCiD logo [2];  [3];  [4]; ORCiD logo [5]
  1. Department of Chemistry and James Franck Institute, University of Chicago, Chicago, Illinois 60637, United States
  2. Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
  3. Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, United States
  4. Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, United States; Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
  5. Department of Chemistry and James Franck Institute, University of Chicago, Chicago, Illinois 60637, United States; Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, United States
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
National Science Foundation (NSF); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); Air Force Research Laboratory (AFRL) - Air Force Office of Scientific Research (AFOSR); US Department of the Navy, Office of Naval Research (ONR)
OSTI Identifier:
1414429
DOE Contract Number:  
AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nano Letters; Journal Volume: 17; Journal Issue: 3
Country of Publication:
United States
Language:
English
Subject:
Colloidal Nanocrystals; Excitonic Transitions; Gallium Arsenide; Lattice Disorder; Molten Salt; Raman Spectroscopy; Transient Absorption

Citation Formats

Srivastava, Vishwas, Liu, Wenyong, Janke, Eric M., Kamysbayev, Vladislav, Filatov, Alexander S., Sun, Cheng-Jun, Lee, Byeongdu, Rajh, Tijana, Schaller, Richard D., and Talapin, Dmitri V. Understanding and Curing Structural Defects in Colloidal GaAs Nanocrystals. United States: N. p., 2017. Web. doi:10.1021/acs.nanolett.7b00481.
Srivastava, Vishwas, Liu, Wenyong, Janke, Eric M., Kamysbayev, Vladislav, Filatov, Alexander S., Sun, Cheng-Jun, Lee, Byeongdu, Rajh, Tijana, Schaller, Richard D., & Talapin, Dmitri V. Understanding and Curing Structural Defects in Colloidal GaAs Nanocrystals. United States. doi:10.1021/acs.nanolett.7b00481.
Srivastava, Vishwas, Liu, Wenyong, Janke, Eric M., Kamysbayev, Vladislav, Filatov, Alexander S., Sun, Cheng-Jun, Lee, Byeongdu, Rajh, Tijana, Schaller, Richard D., and Talapin, Dmitri V. Wed . "Understanding and Curing Structural Defects in Colloidal GaAs Nanocrystals". United States. doi:10.1021/acs.nanolett.7b00481.
@article{osti_1414429,
title = {Understanding and Curing Structural Defects in Colloidal GaAs Nanocrystals},
author = {Srivastava, Vishwas and Liu, Wenyong and Janke, Eric M. and Kamysbayev, Vladislav and Filatov, Alexander S. and Sun, Cheng-Jun and Lee, Byeongdu and Rajh, Tijana and Schaller, Richard D. and Talapin, Dmitri V.},
abstractNote = {Nearly three decades since the first report on the synthesis of colloidal GaAs nanocrystals (NCs), the preparation and properties of this material remain highly controversial. Traditional synthetic routes either fail to produce the GaAs phase or result in materials that do not show expected optical properties such as excitonic transitions. In this work, we demonstrate a variety of synthetic routes toward crystalline GaAs NCs. By using a combination of Raman, EXAFS and transient absorption spectroscopies, we conclude that unusual optical properties of 2 colloidal GaAs NCs can be related to the presence of vacancies and lattice disorder. We introduce novel molten salt based annealing approach to alleviate these structural defects and show the emergence of size-dependent excitonic transitions in colloidal GaAs quantum dots.},
doi = {10.1021/acs.nanolett.7b00481},
journal = {Nano Letters},
number = 3,
volume = 17,
place = {United States},
year = {Wed Feb 22 00:00:00 EST 2017},
month = {Wed Feb 22 00:00:00 EST 2017}
}