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Transition metal dichalcogenide growth via close proximity precursor supply.

O'Brien M, McEvoy N, Hallam T, Kim HY, Berner NC, Hanlon D, Lee K, Coleman JN, Duesberg GS - Sci Rep (2014)

Bottom Line: TMD monolayers were realized using a close proximity precursor supply in a CVD microreactor setup.A model describing the growth mechanism, which is capable of producing TMD monolayers on arbitrary substrates, is presented.Furthermore, through patterning of the precursor supply, we achieve patterned growth of monolayer TMDs in defined locations, which could be adapted for the facile production of electronic device components.

View Article: PubMed Central - PubMed

Affiliation: 1] School of Chemistry, Trinity College Dublin, Dublin 2, Ireland [2] Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) and Advanced Materials and BioEngineering Research (AMBER) Centre, Trinity College Dublin, Dublin 2, Ireland.

ABSTRACT
Reliable chemical vapour deposition (CVD) of transition metal dichalcogenides (TMDs) is currently a highly pressing research field, as numerous potential applications rely on the production of high quality films on a macroscopic scale. Here, we show the use of liquid phase exfoliated nanosheets and patterned sputter deposited layers as solid precursors for chemical vapour deposition. TMD monolayers were realized using a close proximity precursor supply in a CVD microreactor setup. A model describing the growth mechanism, which is capable of producing TMD monolayers on arbitrary substrates, is presented. Raman spectroscopy, photoluminescence, X-ray photoelectron spectroscopy, atomic force microscopy, transmission electron microscopy, scanning electron microscopy and electrical transport measurements reveal the high quality of the TMD samples produced. Furthermore, through patterning of the precursor supply, we achieve patterned growth of monolayer TMDs in defined locations, which could be adapted for the facile production of electronic device components.

No MeSH data available.


Related in: MedlinePlus

(a) Optical image of a polycrystalline MoS2 continuous layer with minimal subsequent island growth on the terminated monolayer. A scratch has been introduced to show contrast with the underlying SiO2 layer. (b) InLens SEM image showing the presence of grain boundaries. Scale bar is 2 µm. (c) HRTEM image of highly crystalline monolayer MoS2, showing hexagonal crystal symmetry. Diffraction pattern inset further shows high quality and crystallinity of the monolayer. Scale bar for diffraction pattern is 2 nm-1. (d) XPS spectrum of the Mo 3d core-level of a large area monolayer MoS2 film. (e) Schematic of furnace setup. Sulfur powder is melted downstream and flowed through the microreactor (f) Schematic of CVD microreactor formed between the seed and target substrates, where sulfur reacts with MoO3 nanosheets to form MoS2 layers on the top substrate.
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f1: (a) Optical image of a polycrystalline MoS2 continuous layer with minimal subsequent island growth on the terminated monolayer. A scratch has been introduced to show contrast with the underlying SiO2 layer. (b) InLens SEM image showing the presence of grain boundaries. Scale bar is 2 µm. (c) HRTEM image of highly crystalline monolayer MoS2, showing hexagonal crystal symmetry. Diffraction pattern inset further shows high quality and crystallinity of the monolayer. Scale bar for diffraction pattern is 2 nm-1. (d) XPS spectrum of the Mo 3d core-level of a large area monolayer MoS2 film. (e) Schematic of furnace setup. Sulfur powder is melted downstream and flowed through the microreactor (f) Schematic of CVD microreactor formed between the seed and target substrates, where sulfur reacts with MoO3 nanosheets to form MoS2 layers on the top substrate.

Mentions: Here, we present the synthesis of TMD monolayers by utilizing a close proximity precursor supply of liquid phase exfoliated MoO3 nanosheets. This was achieved by drop casting the nanosheets onto substrates, and then placing the growth substrates face down on top of them, as illustrated in Fig. 1(e) and (f). Liquid phase exfoliated materials form stable dispersions that can be used as inks for printing devices such as photodiodes39 and photodetectors40. Here we demonstrate their potential for use as controllable solid CVD precursors. The microreactor setup can be reproduced in a variety of CVD systems due to the simplicity of the approach. Additionally, we demonstrate that this process can be adapted to synthesize patterned TMDs by pre-patterning the precursor layer.


Transition metal dichalcogenide growth via close proximity precursor supply.

O'Brien M, McEvoy N, Hallam T, Kim HY, Berner NC, Hanlon D, Lee K, Coleman JN, Duesberg GS - Sci Rep (2014)

(a) Optical image of a polycrystalline MoS2 continuous layer with minimal subsequent island growth on the terminated monolayer. A scratch has been introduced to show contrast with the underlying SiO2 layer. (b) InLens SEM image showing the presence of grain boundaries. Scale bar is 2 µm. (c) HRTEM image of highly crystalline monolayer MoS2, showing hexagonal crystal symmetry. Diffraction pattern inset further shows high quality and crystallinity of the monolayer. Scale bar for diffraction pattern is 2 nm-1. (d) XPS spectrum of the Mo 3d core-level of a large area monolayer MoS2 film. (e) Schematic of furnace setup. Sulfur powder is melted downstream and flowed through the microreactor (f) Schematic of CVD microreactor formed between the seed and target substrates, where sulfur reacts with MoO3 nanosheets to form MoS2 layers on the top substrate.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4260218&req=5

f1: (a) Optical image of a polycrystalline MoS2 continuous layer with minimal subsequent island growth on the terminated monolayer. A scratch has been introduced to show contrast with the underlying SiO2 layer. (b) InLens SEM image showing the presence of grain boundaries. Scale bar is 2 µm. (c) HRTEM image of highly crystalline monolayer MoS2, showing hexagonal crystal symmetry. Diffraction pattern inset further shows high quality and crystallinity of the monolayer. Scale bar for diffraction pattern is 2 nm-1. (d) XPS spectrum of the Mo 3d core-level of a large area monolayer MoS2 film. (e) Schematic of furnace setup. Sulfur powder is melted downstream and flowed through the microreactor (f) Schematic of CVD microreactor formed between the seed and target substrates, where sulfur reacts with MoO3 nanosheets to form MoS2 layers on the top substrate.
Mentions: Here, we present the synthesis of TMD monolayers by utilizing a close proximity precursor supply of liquid phase exfoliated MoO3 nanosheets. This was achieved by drop casting the nanosheets onto substrates, and then placing the growth substrates face down on top of them, as illustrated in Fig. 1(e) and (f). Liquid phase exfoliated materials form stable dispersions that can be used as inks for printing devices such as photodiodes39 and photodetectors40. Here we demonstrate their potential for use as controllable solid CVD precursors. The microreactor setup can be reproduced in a variety of CVD systems due to the simplicity of the approach. Additionally, we demonstrate that this process can be adapted to synthesize patterned TMDs by pre-patterning the precursor layer.

Bottom Line: TMD monolayers were realized using a close proximity precursor supply in a CVD microreactor setup.A model describing the growth mechanism, which is capable of producing TMD monolayers on arbitrary substrates, is presented.Furthermore, through patterning of the precursor supply, we achieve patterned growth of monolayer TMDs in defined locations, which could be adapted for the facile production of electronic device components.

View Article: PubMed Central - PubMed

Affiliation: 1] School of Chemistry, Trinity College Dublin, Dublin 2, Ireland [2] Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) and Advanced Materials and BioEngineering Research (AMBER) Centre, Trinity College Dublin, Dublin 2, Ireland.

ABSTRACT
Reliable chemical vapour deposition (CVD) of transition metal dichalcogenides (TMDs) is currently a highly pressing research field, as numerous potential applications rely on the production of high quality films on a macroscopic scale. Here, we show the use of liquid phase exfoliated nanosheets and patterned sputter deposited layers as solid precursors for chemical vapour deposition. TMD monolayers were realized using a close proximity precursor supply in a CVD microreactor setup. A model describing the growth mechanism, which is capable of producing TMD monolayers on arbitrary substrates, is presented. Raman spectroscopy, photoluminescence, X-ray photoelectron spectroscopy, atomic force microscopy, transmission electron microscopy, scanning electron microscopy and electrical transport measurements reveal the high quality of the TMD samples produced. Furthermore, through patterning of the precursor supply, we achieve patterned growth of monolayer TMDs in defined locations, which could be adapted for the facile production of electronic device components.

No MeSH data available.


Related in: MedlinePlus