Published In

The Journal of Chemical Physics

Document Type

Article

Publication Date

6-28-2016

Subjects

Scanning tunneling microscopy, Nanosilicon, Nanocrystals, Electronic structure, Energy gaps (Physics)

Abstract

We present results of a scanning tunneling spectroscopy (STS) study of the impact of dehydrogenation on the electronic structures of hydrogen-passivated silicon nanocrystals (SiNCs) supported on the Au(111)surface. Gradual dehydrogenation is achieved by injecting high-energy electrons into individual SiNCs, which results, initially, in reduction of the electronic bandgap, and eventually produces midgap electronic states. We use theoretical calculations to show that the STS spectra of midgap states are consistent with the presence of silicon dangling bonds, which are found in different charge states. Our calculations also suggest that the observed initial reduction of the electronic bandgap is attributable to the SiNC surface reconstruction induced by conversion of surface dihydrides to monohydrides due to hydrogen desorption. Our results thus provide the first visualization of the SiNC electronic structure evolution induced by dehydrogenation and provide direct evidence for the existence of diverse dangling bond states on the SiNC surfaces.

Description

Copyright 2016 The Author(s). Published by AIP Publishing. Archived with permission.

The definitive version can be found at the Publisher site. http://dx.doi.org/10.1063/1.4954833.

DOI

10.1063/1.4954833

Persistent Identifier

http://archives.pdx.edu/ds/psu/17807

Available for download on Wednesday, June 28, 2017

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