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Enhanced quantum efficiency from a mosaic of two dimensional MoS2 formed onto aminosilane functionalised substrates

Version 2 2024-06-13, 10:54
Version 1 2017-10-17, 14:43
journal contribution
posted on 2024-06-13, 10:54 authored by Y Wang, E Della Gaspera, BJ Carey, P Atkin, KJ Berean, RM Clark, IS Cole, ZQ Xu, Y Zhang, Q Bao, JZ Ou, T Daeneke, K Kalantar-Zadeh
Developing scalable methods of growing two dimensional molybdenum disulphide (2D MoS2) with strong optical properties, on any desired substrates, is a necessary step towards industrial uptake of this material for optical applications. In this study, Si/SiO2 substrates were functionalised using self-assembled monolayers of three different aminosilanes with various numbers of amine groups and molecular lengths as underlayers for enhancing the adherence of the molybdenum precursor. The tetrahedral [MoS4](2-) anion groups from the molybdenum precursor were bonded on these silanised Si/SiO2 substrates afterwards. The substrates were then treated with a combined thermolysis and sulphurisation step. The results showed that silanisation of the substrates using the longest chains and the largest number of amine groups provided a good foundation to grow quasi 2D MoS2 made from adjacent flakes in a mosaic formation. Microscopy and spectroscopy investigations revealed that these quasi 2D MoS2 formed using this long chain aminosilane resulted in flakes with lateral dimensions in micron and submicron ranges composed of adjoining MoS2 pieces of 20 to 60 nm in lateral dimensions, dominantly made of 3 to 5 MoS2 fundamental layers. The obtained quasi 2D MoS2 shows a high internal quantum efficiency of 2.6% associated with the quantum confinement effect and high stoichiometry of the adjoining nanoflakes that form the structure of the sheets. The synthesis technique in this study is reliable and facile and offers a procedure to form large, scalable and patternable quasi 2D MoS2 sheets on various substrates with enhanced optical properties for practical applications.

History

Journal

Nanoscale

Volume

8

Pagination

12258-12266

Location

England

ISSN

2040-3364

eISSN

2040-3372

Language

English

Publication classification

C Journal article, C1.1 Refereed article in a scholarly journal

Copyright notice

2016, The Royal Society of Chemistry

Issue

24

Publisher

ROYAL SOC CHEMISTRY