Mapping of Defects in Individual Silicon Nanocrystals Using Real-Space Spectroscopy.
2016 (English)In: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 7, no 6, 1047-1054 p.Article in journal (Refereed) Published
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.
Place, publisher, year, edition, pages
2016. Vol. 7, no 6, 1047-1054 p.
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:uu:diva-283342DOI: 10.1021/acs.jpclett.6b00176ISI: 000372561900017PubMedID: 26938674OAI: oai:DiVA.org:uu-283342DiVA: diva2:918949
FunderSwedish Research CouncilGöran Gustafsson Foundation for Research in Natural Sciences and MedicineEU, FP7, Seventh Framework ProgrammeSwedish National Infrastructure for Computing (SNIC)