Communication: Visualization and spectroscopy of defects induced by dehydrogenation in individual silicon nanocrystals
2016 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 144, no 24, 241102Article in journal (Refereed) PublishedText
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. Published by AIP Publishing.
Place, publisher, year, edition, pages
2016. Vol. 144, no 24, 241102
Atom and Molecular Physics and Optics Materials Chemistry
IdentifiersURN: urn:nbn:se:uu:diva-300064DOI: 10.1063/1.4954833ISI: 000379166100002OAI: oai:DiVA.org:uu-300064DiVA: diva2:950751
FunderSwedish Research CouncilStandUpGöran Gustafsson Foundation for promotion of scientific research at Uppala University and Royal Institute of TechnologyEU, European Research CouncilSwedish National Infrastructure for Computing (SNIC)eSSENCE - An eScience Collaboration