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Passivation of GaAs Nanocrystals by Chemical Functionalization

Traub, Matthew C. and Biteen, Julie S. and Brunschwig, Bruce S. and Lewis, Nathan S. (2008) Passivation of GaAs Nanocrystals by Chemical Functionalization. Journal of the American Chemical Society, 130 (3). pp. 955-964. ISSN 0002-7863. https://resolver.caltech.edu/CaltechAUTHORS:20170426-143025493

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Abstract

The effective use of nanocrystalline semiconductors requires control of the chemical and electrical properties of their surfaces. We describe herein a chemical functionalization procedure to passivate surface states on GaAs nanocrystals. Cl-terminated GaAs nanocrystals have been produced by anisotropic etching of oxide-covered GaAs nanocrystals with 6 M HCl(aq). The Cl-terminated GaAs nanocrystals were then functionalized by reaction with hydrazine or sodium hydrosulfide. X-ray photoelectron spectroscopic measurements revealed that the surfaces of the Cl-, hydrazine-, and sulfide-treated nanocrystals were As-rich, due to significant amounts of As^0. However, no As^0 was observed in the photoelectron spectra after the hydrazine-terminated nanocrystals were annealed at 350° C under vacuum. After the anneal, the N 1s peak of hydrazine-exposed GaAs nanocrystals shifted to 3.2 eV lower binding energy. This shift was accompanied by the appearance of a Ga 3d peak shifted 1.4 eV from the bulk value, consistent with the hypothesis that a gallium oxynitride capping layer had been formed on the nanocrystals during the annealing process. The band gap photoluminescence (PL) was weak from the Cl- and hydrazine- or sulfide-terminated nanocrystals, but the annealed nanocrystals displayed strongly enhanced band-edge PL, indicating that the surface states of GaAs nanocrystals were effectively passivated by this two-step, wet chemical treatment.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1021/ja076034pDOIArticle
http://pubs.acs.org/doi/abs/10.1021/ja076034pPublisherArticle
ORCID:
AuthorORCID
Brunschwig, Bruce S.0000-0002-6135-6727
Lewis, Nathan S.0000-0001-5245-0538
Additional Information:© 2008 American Chemical Society. Received August 10, 2007. Publication Date (Web): January 3, 2008. We gratefully acknowledge the U.S. Department of Energy, Office of Basic Energy Sciences, for support of this work. We thank Dr. Carol Garland for assistance collecting TEM images. This research was carried out in part at the Molecular Materials Research Center in the Beckman Institute at Caltech.
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Funding AgencyGrant Number
Department of Energy (DOE)UNSPECIFIED
Issue or Number:3
Record Number:CaltechAUTHORS:20170426-143025493
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20170426-143025493
Official Citation:Passivation of GaAs Nanocrystals by Chemical Functionalization Matthew C. Traub, Julie S. Biteen, Bruce S. Brunschwig, and Nathan S. Lewis Journal of the American Chemical Society 2008 130 (3), 955-964 DOI: 10.1021/ja076034p
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:76958
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:26 Apr 2017 23:07
Last Modified:03 Oct 2019 17:51

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