Experiments with extrinsic Si(111) surfaces

Cs adsorption at room temperature on Si(111) terminated with hydrogen and oxygen

P. Morgen*, P. E. Hansen, K. Pedersen

*Kontaktforfatter for dette arbejde

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

The characteristic intrinsic properties of silicon surfaces are strongly related to the dangling bonds, and their presence again are due to the different possible reconstructions. It is possible to create surfaces on which the dangling bonds are removed or changed by adsorption of gas atoms or metal atoms. Such surfaces may exhibit new, tailorable properties, making them interesting for device applications. In this report, the properties of hydrogen and oxygen terminated n-type Si(111) surfaces are compared with respect to Cs adsorption, and seen against those of the Si(111) 7 × 7 surface. The techniques include core level and valence band photoemission with synchrotron radiation at the Aarhus storage ring, spectroscopic optical second harmonic generation and LEED. It is found that the hydrogen terminated (1 × 1) surface has practically no free dangling bonds and is unpinned. As a result the position of the band edge is strongly lowered with Cs adsorption. This surface is stable against Cs adsorption and shows a highly enhanced electron emission upon radiation with photons as a result of the lowered workfunction. The (monolayer) oxygen terminated surface is electronically stable and shows a pinning of the surface potential resisting the movement of the band edge with adsorption of Cs, despite a reaction between Cs and oxygen. For the clean surface direct interactions between Cs and Si surface atoms create new interface states at the Fermi level. A number of less significant differences between these surfaces are also pointed out.

OriginalsprogEngelsk
TidsskriftApplied Surface Science
Vol/bind117-118
Sider (fra-til)72-76
Antal sider5
ISSN0169-4332
DOI
StatusUdgivet - 2. jun. 1997

Fingeraftryk

Adsorption
Hydrogen
Oxygen
Experiments
Dangling bonds
Temperature
Atoms
Core levels
Interface states
Storage rings
Electron emission
Surface potential
Photoemission
Harmonic generation
Valence bands
Synchrotron radiation
Fermi level
Monolayers
Photons
Radiation

Citer dette

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title = "Experiments with extrinsic Si(111) surfaces: Cs adsorption at room temperature on Si(111) terminated with hydrogen and oxygen",
abstract = "The characteristic intrinsic properties of silicon surfaces are strongly related to the dangling bonds, and their presence again are due to the different possible reconstructions. It is possible to create surfaces on which the dangling bonds are removed or changed by adsorption of gas atoms or metal atoms. Such surfaces may exhibit new, tailorable properties, making them interesting for device applications. In this report, the properties of hydrogen and oxygen terminated n-type Si(111) surfaces are compared with respect to Cs adsorption, and seen against those of the Si(111) 7 × 7 surface. The techniques include core level and valence band photoemission with synchrotron radiation at the Aarhus storage ring, spectroscopic optical second harmonic generation and LEED. It is found that the hydrogen terminated (1 × 1) surface has practically no free dangling bonds and is unpinned. As a result the position of the band edge is strongly lowered with Cs adsorption. This surface is stable against Cs adsorption and shows a highly enhanced electron emission upon radiation with photons as a result of the lowered workfunction. The (monolayer) oxygen terminated surface is electronically stable and shows a pinning of the surface potential resisting the movement of the band edge with adsorption of Cs, despite a reaction between Cs and oxygen. For the clean surface direct interactions between Cs and Si surface atoms create new interface states at the Fermi level. A number of less significant differences between these surfaces are also pointed out.",
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author = "P. Morgen and Hansen, {P. E.} and K. Pedersen",
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Experiments with extrinsic Si(111) surfaces : Cs adsorption at room temperature on Si(111) terminated with hydrogen and oxygen. / Morgen, P.; Hansen, P. E.; Pedersen, K.

I: Applied Surface Science, Bind 117-118, 02.06.1997, s. 72-76.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Experiments with extrinsic Si(111) surfaces

T2 - Cs adsorption at room temperature on Si(111) terminated with hydrogen and oxygen

AU - Morgen, P.

AU - Hansen, P. E.

AU - Pedersen, K.

PY - 1997/6/2

Y1 - 1997/6/2

N2 - The characteristic intrinsic properties of silicon surfaces are strongly related to the dangling bonds, and their presence again are due to the different possible reconstructions. It is possible to create surfaces on which the dangling bonds are removed or changed by adsorption of gas atoms or metal atoms. Such surfaces may exhibit new, tailorable properties, making them interesting for device applications. In this report, the properties of hydrogen and oxygen terminated n-type Si(111) surfaces are compared with respect to Cs adsorption, and seen against those of the Si(111) 7 × 7 surface. The techniques include core level and valence band photoemission with synchrotron radiation at the Aarhus storage ring, spectroscopic optical second harmonic generation and LEED. It is found that the hydrogen terminated (1 × 1) surface has practically no free dangling bonds and is unpinned. As a result the position of the band edge is strongly lowered with Cs adsorption. This surface is stable against Cs adsorption and shows a highly enhanced electron emission upon radiation with photons as a result of the lowered workfunction. The (monolayer) oxygen terminated surface is electronically stable and shows a pinning of the surface potential resisting the movement of the band edge with adsorption of Cs, despite a reaction between Cs and oxygen. For the clean surface direct interactions between Cs and Si surface atoms create new interface states at the Fermi level. A number of less significant differences between these surfaces are also pointed out.

AB - The characteristic intrinsic properties of silicon surfaces are strongly related to the dangling bonds, and their presence again are due to the different possible reconstructions. It is possible to create surfaces on which the dangling bonds are removed or changed by adsorption of gas atoms or metal atoms. Such surfaces may exhibit new, tailorable properties, making them interesting for device applications. In this report, the properties of hydrogen and oxygen terminated n-type Si(111) surfaces are compared with respect to Cs adsorption, and seen against those of the Si(111) 7 × 7 surface. The techniques include core level and valence band photoemission with synchrotron radiation at the Aarhus storage ring, spectroscopic optical second harmonic generation and LEED. It is found that the hydrogen terminated (1 × 1) surface has practically no free dangling bonds and is unpinned. As a result the position of the band edge is strongly lowered with Cs adsorption. This surface is stable against Cs adsorption and shows a highly enhanced electron emission upon radiation with photons as a result of the lowered workfunction. The (monolayer) oxygen terminated surface is electronically stable and shows a pinning of the surface potential resisting the movement of the band edge with adsorption of Cs, despite a reaction between Cs and oxygen. For the clean surface direct interactions between Cs and Si surface atoms create new interface states at the Fermi level. A number of less significant differences between these surfaces are also pointed out.

KW - Cs adsorption

KW - Hydrogen and oxygen termination

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