Enhanced quantum efficiency from a mosaic of two dimensional MoS2 formed onto aminosilane functionalised substrates.
Enhanced quantum efficiency from a mosaic of two dimensional MoS2 formed onto aminosilane functionalised substrates.
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DOI：
10.1039/c6nr02197b
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发表时间：
2016-06
期刊：
影响因子：
6.7
通讯作者：
Yichao Wang;E. Della Gaspera;Benjamin J. Carey;P. Atkin;K. Berean;Rhiannon M. Clark;I. Cole;Zai‐Quan Xu;Yupeng Zhang;Q. Bao;J. Ou;T. Daeneke;K. Kalantar-zadeh
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文献类型：
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作者：
Yichao Wang;E. Della Gaspera;Benjamin J. Carey;P. Atkin;K. Berean;Rhiannon M. Clark;I. Cole;Zai‐Quan Xu;Yupeng Zhang;Q. Bao;J. Ou;T. Daeneke;K. Kalantar-zadeh
开发在任何所需衬底上生长具有强光学特性的二维二硫化钼（2D MoS 2）的可扩展方法是工业上采用这种材料用于光学应用的必要步骤。在这项研究中，Si/SiO2基板功能化使用自组装单层的三种不同的氨基硅烷与各种数量的胺基和分子长度作为底层，以提高钼前体的粘附性。随后将来自钼前体的四面体[MoS 4]（2-）阴离子基团键合在这些硅烷化的Si/SiO2衬底上。然后用组合的热处理和硫化步骤处理基材。结果表明，使用最长的链和最大数量的胺基的衬底的硅烷化提供了良好的基础，以生长准2D MoS 2由相邻的薄片在马赛克形成。显微镜和光谱学研究显示，使用这种长链氨基硅烷形成的这些准2D MoS 2导致横向尺寸在微米和亚微米范围内的薄片，其由横向尺寸为20至60 nm的邻接MoS 2片组成，主要由3至5个MoS 2基本层制成。所获得的准2D MoS 2显示出与形成片材结构的相邻纳米片的量子限制效应和高化学计量比相关的2.6%的高内部量子效率。在这项研究中的合成技术是可靠的，简便的，并提供了一个程序，以形成大的，可扩展的和可图案化的准二维二硫化钼片在各种基板上具有增强的光学性能的实际应用。
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.