Sponsor
The STM instrument used in this work was constructed with support from the National Science Foundation under Grant DMR-0960211. B.N.T. and G.V.N. gratefully acknowledge support from the Center for Sustainable Materials Chemistry through the NSF CCI Grant CHE-1102637. D.A.K., J.M.M., and C.F.G. acknowledge support from NSF Grant CHE- 1454036. A.M.G acknowledges the Burroughs Wellcome Fund (Award Number 1007294.01) for financial support. O.E. acknowledges support from the Swedish Research Council and STANDUPP. J.R. acknowledges support from the Swedish Research Council and the Göran Gustafsson’s Foundation. V.K. acknowledges support from the EU’s seventh Framework Programme SNAPSUN, the Swedish National Infrastructure for Computing (SNIC), and eSSENCE.
Published In
The Journal of Physical Chemistry Letters
Document Type
Article
Publication Date
3-2016
Subjects
Scanning tunneling microscopy, Nanosilicon, Nanocrystals, Electronic structure
Abstract
The photophysical properties of silicon semiconductor nanocrystals (SiNCs) are extremely sensitive to the presence of surface chemical defects, many of which are easily produced by oxidation under ambient conditions. The diversity of chemical structures of such defects and the lack of tools capable of probing individual defects continue to impede understanding of the roles of these defects in SiNC photophysics. We use scanning tunneling spectroscopy to study the impact of surface defects on the electronic structures of hydrogen-passivated SiNCs supported on the Au(111) surface. Spatial maps of the local electronic density of states (LDOS) produced by our measurements allowed us to identify locally enhanced defect-induced states as well as quantum-confined states delocalized throughout the SiNC volume. We use theoretical calculations to show that the LDOS spectra associated with the observed defects are attributable to Si–O–Si bridged oxygen or Si–OH surface defects.
DOI
10.1021/acs.jpclett.6b00176
Persistent Identifier
http://archives.pdx.edu/ds/psu/18828
Citation Details
Kislitsyn, D. A.; Kocevski, V.; Mills, J. M.; Chiu, S.; Gervasi, C. F.; Taber, B. N.; Rosenfield, A. E.; Eriksson, O.; Rusz, J.; Goforth, A. M.; Nazin, G. V. Mapping of Defects in Individual Silicon Nanocrystals Using Real-Space Spectroscopy. J. Phys. Chem. Lett. 2016, 7 (6), 1047–1054.
Description
This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes.
© 2016 American Chemical Society
Originally published in the The Journal of Physical Chemistry Letters and can be found online at: http://dx.doi.org/10.1021/acs.jpclett.6b00176