Phthalocyanine thin films on Si(111)

Franz, Martin

doi:10.1016/j.ica.2023.121771

“…In terms of organic layers, phthalocyanines and their surface chemistry are a particularly interesting field . There are numerous studies on phthalocyanines on the Si(111)(7 × 7) surface, but the growth of ordered molecular films could not be demonstrated . However, the formation of highly ordered phthalocyanine films can be promoted by using Si(111) surfaces modified with various elements, such as H, , B, Ag, , In, or Tl. , …”

Section: Introductionmentioning

confidence: 99%

“…12 There are numerous studies on phthalocyanines on the Si(111)(7 × 7) surface, but the growth of ordered molecular films could not be demonstrated. 13 However, the formation of highly ordered phthalocyanine films can be promoted by using Si(111) surfaces modified with various elements, 13 such as H, 14,15 B, 16 Ag, 17,18 In, 19 or Tl. 20,21 Here we demonstrate that rare earth modified silicon surfaces have a high potential for enabling an ordered organic film growth.…”

Section: ■ Introductionmentioning

confidence: 99%

A Rare Earth Modified Silicon Surface as a Template for Ordered Organic Growth

Kubicki,

Franz,

Dähne

2024

J. Phys. Chem. C

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Organic monolayers on silicon represent a promising candidate to enhance or modify the capabilities of silicon-based (opto)electronic devices. However, the formation of ordered organic films on silicon surfaces is usually hindered by their high dangling bond density, so that an appropriate surface modification is required. Here we demonstrate the high potential of a rare earth modification for promoting an ordered growth. Using scanning tunneling microscopy, we show that a terbium modified Si(111) surface enables the formation of highly ordered cobalt phthalocyanine monolayers consisting of differently orientated domains with an almost 4-fold symmetry and determine its periodic structure with respect to the substrate.

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“…The Si(111)

{\sqrt 3 \times \sqrt 3 }

R30°‐B surface (Si(111)‐B) was chosen as a substrate as it has been demonstrated to be particularly suitable for the self‐assembly of organic films [19,20,54–60] . On this surface, the otherwise highly reactive dangling bond sites are deactivated due to the subsurface incorporation of B atoms [61,62] .…”

Section: Introductionmentioning

confidence: 99%

“…[26,27] The Si(111) ffi ffi ffi 3 p � ffi ffi ffi 3 p R30°-B surface (Si(111)-B) was chosen as a substrate as it has been demonstrated to be particularly suitable for the self-assembly of organic films. [19,20,[54][55][56][57][58][59][60] On this surface, the otherwise highly reactive dangling bond sites are deactivated due to the subsurface incorporation of B atoms. [61,62] The structure model and scanning tunneling microscopy (STM) results of the clean Si(111)-B surface are presented in Figure S1.…”

Section: Introductionmentioning

confidence: 99%

N‐Heterocyclic Olefins on a Silicon Surface

Das,

Hogan,

Zielinski

et al. 2023

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The adsorption of N‐heterocyclic olefins (NHOs) on silicon is investigated in a combined scanning tunneling microscopy, X‐ray photoelectron spectroscopy, and density functional theory study. We find that both of the studied NHOs bind covalently, with ylidic character, to the silicon adatoms of the substrate and exhibit good thermal stability. The adsorption geometry strongly depends on the N‐substituents: for large N‐substituents, an upright adsorption geometry is favored, while a flat‐lying geometry is found for the NHO with smaller wingtips. These different geometries strongly influence the quality and properties of the obtained monolayers. The upright geometry leads to the formation of ordered monolayers, whereas the flat‐lying NHOs yield a mostly disordered, but denser, monolayer. The obtained monolayers both show large work function reductions, as the higher density of the flat‐lying monolayer is found to compensate for the smaller vertical dipole moments. Our findings offer new prospects in the design of tailor‐made ligand structures in organic electronics and optoelectronics, catalysis, and material science.

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N‐Heterocyclic Olefins on a Silicon Surface

Das,

Hogan,

Zielinski

et al. 2023

Angewandte Chemie

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The adsorption of N‐heterocyclic olefins (NHOs) on silicon is investigated in a combined scanning tunneling microscopy, X‐ray photoelectron spectroscopy, and density functional theory study. We find that both of the studied NHOs bind covalently, with ylidic character, to the silicon adatoms of the substrate and exhibit good thermal stability. The adsorption geometry strongly depends on the N‐substituents: for large N‐substituents, an upright adsorption geometry is favored, while a flat‐lying geometry is found for the NHO with smaller wingtips. These different geometries strongly influence the quality and properties of the obtained monolayers. The upright geometry leads to the formation of ordered monolayers, whereas the flat‐lying NHOs yield a mostly disordered, but denser, monolayer. The obtained monolayers both show large work function reductions, as the higher density of the flat‐lying monolayer is found to compensate for the smaller vertical dipole moments. Our findings offer new prospects in the design of tailor‐made ligand structures in organic electronics and optoelectronics, catalysis, and material science.

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Phthalocyanine thin films on Si(111)

Cited by 3 publications

References 177 publications

A Rare Earth Modified Silicon Surface as a Template for Ordered Organic Growth

A Rare Earth Modified Silicon Surface as a Template for Ordered Organic Growth

N‐Heterocyclic Olefins on a Silicon Surface

N‐Heterocyclic Olefins on a Silicon Surface

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