Issue 6, 2020

Direct bilayer growth: a new growth principle for a novel WSe2 homo-junction and bilayer WSe2 growth

Abstract

Homo-junction and multi-layer structures of transition metal chalcogenide (TMD) materials provide great flexibility for band-structure engineering and designing photoelectric devices. However, the knowledge of van der Waals epitaxy growth limits the development of these heterostructures. Herein, we employed the chemical vapor deposition (CVD) growth strategy to synthesize novel WSe2 homo-junction samples with a triangular monolayer in the center and three AA stacking bilayer flakes connected to the vertexes of the monolayer. The emitted photon energy from the bilayer near the junction showed a blueshift in energy of up to 24 meV compared with bare bilayer WSe2, confirming the charge transfer effect from monolayer to bilayer WSe2. Further growth studies revealed the shape evolution from WSe2 homo-junction to bilayer. The whole homo-junction formation and evolution process cannot be explained by the traditional layer-by-layer growth mechanism. Instead, a direct bilayer growth approach is proposed to explain the bilayer formation and evolution at the vertexes of the bottom layer of WSe2. These findings suggest that the growth of bilayer TMDs is more complex than our previous understanding. This work presents deepens insight into van der Waals epitaxy growth, and thus is valuable for guiding the fabrication of novel homo-junctions for both fundamental science and optoelectronic applications.

Graphical abstract: Direct bilayer growth: a new growth principle for a novel WSe2 homo-junction and bilayer WSe2 growth

Supplementary files

Article information

Article type
Paper
Submitted
20 Nov 2019
Accepted
13 Jan 2020
First published
14 Jan 2020

Nanoscale, 2020,12, 3715-3722

Direct bilayer growth: a new growth principle for a novel WSe2 homo-junction and bilayer WSe2 growth

L. Fang, X. Yuan, K. Liu, L. Li, P. Zhou, W. Ma, H. Huang, J. He and S. Tao, Nanoscale, 2020, 12, 3715 DOI: 10.1039/C9NR09874G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements