Synthesis of Epitaxial Single-Layer MoS2 on Au(111)

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• 作者：Signe S. Gr酶nborg ; S酶ren Ulstrup ; Marco Bianchi ; Maciej Dendzik ; Charlotte E. Sanders ; Jeppe V. Lauritsen ; Philip Hofmann ; Jill A. Miwa
• 刊名：Langmuir
• 出版年：2015
• 出版时间：September 8, 2015
• 年：2015
• 卷：31
• 期：35
• 页码：9700-9706
• 全文大小：423K
• ISSN：1520-5827

文摘

We present a method for synthesizing large area epitaxial single-layer MoS₂ on the Au(111) surface in ultrahigh vacuum. Using scanning tunneling microscopy and low energy electron diffraction, the evolution of the growth is followed from nanoscale single-layer MoS₂ islands to a continuous MoS₂ layer. An exceptionally good control over the MoS₂ coverage is maintained using an approach based on cycles of Mo evaporation and sulfurization to first nucleate the MoS₂ nanoislands and then gradually increase their size. During this growth process the native herringbone reconstruction of Au(111) is lifted as shown by low energy electron diffraction measurements. Within the MoS₂ islands, we identify domains rotated by 60掳 that lead to atomically sharp line defects at domain boundaries. As the MoS₂ coverage approaches the limit of a complete single layer, the formation of bilayer MoS₂ islands is initiated. Angle-resolved photoemission spectroscopy measurements of both single and bilayer MoS₂ samples show a dramatic change in their band structure around the center of the Brillouin zone. Brief exposure to air after removing the MoS₂ layer from vacuum is not found to affect its quality.