Understanding and Curing Structural Defects in Colloidal GaAs Nanocrystals
- Department of Chemistry and James Franck Institute, University of Chicago, Chicago, Illinois 60637, United States
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
- Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, United States
- Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, United States; Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
- 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
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.
- Research Organization:
- Argonne National Laboratory (ANL)
- Sponsoring Organization:
- National Science Foundation (NSF); USDOE Office of Science - Office of Basic Energy Sciences; Air Force Research Laboratory (AFRL) - Air Force Office of Scientific Research (AFOSR); Office of Naval Research
- DOE Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1414429
- Journal Information:
- Nano Letters, Journal Name: Nano Letters Journal Issue: 3 Vol. 17; ISSN 1530-6984
- Publisher:
- American Chemical Society
- Country of Publication:
- United States
- Language:
- English
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