Controlled synthesis of high-quality crystals of monolayer MoS2 for nanoelectronic device application

• Published in: Science China materials 2016-03, Vol.59 (3), p.182-190
• Main Authors: Yang, Xiaonian, Li, Qiang, Hu, Guofeng, Wang, Zegao, Yang, Zhenyu, Liu, Xingqiang, Dong, Mingdong, Pan, Caofeng
• Format: Article
• Language: English
• Subjects: Chemistry and Materials Science; Chemistry/Food Science; Materials Science
• ISSN: 2095-8226; 2199-4501
• DOI: 10.1007/s40843-016-0130-1

Two-dimensional layered materials have attracted significant interest for their potential applications in electronic and optoelectronics devices. Among them, transition metal dichalcogenides (TMDs), especially molybdenum disulfide (MoS 2 ), is extensively studied because of its unique properties. Monolayer MoS 2 so far can be obtained by mechanical exfoliation or chemical vapor deposition (CVD). However, controllable synthesis of large area monolayer MoS 2 with high quality needs to be improved and their growth mechanism requires more studies. Here we report a systematical study on controlled synthesis of high-quality monolayer MoS 2 single crystals using low pressure CVD. Large-size monolayer MoS 2 triangles with an edge length up to 405 μm were successfully synthesized. The Raman and photoluminescence spectroscopy studies indicate high homogenous optical characteristic of the synthesized monolayer MoS 2 triangles. The transmission electron microscopy results demonstrate that monolayer MoS 2 triangles are single crystals. The back-gated field effect transistors (FETs) fabricated using the as-grown monolayer MoS 2 show typical n-type semiconductor behaviors with carrier mobility up to 21.8 cm 2 V −1 s −1 , indicating excellent electronic property comparing with previously reported CVD grown MoS 2 monolayer. The MoS 2 FETs also show a high photoresponsivity of 7 A W −1 , as well as a fast photo-response time of 20 ms. The improved synthesis method recommended here, which makes material preparation much easier, may strongly promote further research and potential applications.