Hydrogen-assisted step-edge nucleation of MoSe2 monolayers on sapphire substrates.
Nanoscale
; 11(16): 7701-7709, 2019 Apr 23.
Article
en En
| MEDLINE
| ID: mdl-30946393
The fabrication of large-area single crystalline monolayer transition metal dichalcogenides (TMDs) is essential for a range of electric and optoelectronic applications. Chemical vapor deposition (CVD) is a promising method to achieve this goal by employing orientation control or alignment along the crystalline lattice of the substrate such as sapphire. On the other hand, a fundamental understanding of the aligned-growth mechanism of TMDs is limited. In this report, we show that the controlled introduction of H2 during the CVD growth of MoSe2 plays a vital role in the step-edge aligned nucleation on a c-sapphire (0001) substrate. In particular, the MoSe2 domains nucleate along the [112[combining macron]0] step-edge orientation by flowing H2 subsequent to pure Ar. Systematic studies, including the H2 introduction time, flow rate, and substrate temperature, suggest that the step-edge aligned nucleation of MoSe2 can be controlled by the hydrogen concentration on the sapphire substrate. These results offer important insights into controlling the epitaxial growth of 2D materials on a crystalline substrate.
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01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Nanoscale
Año:
2019
Tipo del documento:
Article
Pais de publicación:
Reino Unido