Electronic Properties of MoS2鈥揥S2 Heterostructures Synthesized with Two-Step Lateral Epitaxial Strategy
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- 作者：Kun Chen ; Xi Wan ; Jinxiu Wen ; Weiguang Xie ; Zhiwen Kang ; Xiaoliang Zeng ; Huanjun Chen ; Jian-Bin Xu
- 刊名：ACS Nano
- 出版年：2015
- 出版时间：October 27, 2015
- 年：2015
- 卷：9
- 期：10
- 页码：9868-9876
- 全文大小：632K
- ISSN：1936-086X
文摘
Formation of heterojunctions of transition metal dichalcogenides (TMDs) stimulates wide interest in new device physics and technology by tuning optical and electronic properties of TMDs. TMDs heterojunctions are of scientific and technological interest for exploration of next generation flexible electronics. Herein, we report on a two-step epitaxial ambient-pressure CVD technique to construct in-plane MoS2鈥揥S2 heterostructures. The technique has the potential to artificially control the shape and structure of heterostructures or even to be more potentially extendable to growth of TMD superlattice than that of one-step CVD technique. Moreover, the unique MX2 heterostructure with monolayer MoS2 core wrapped by multilayer WS2 is obtained by the technique, which is entirely different from MX2 heterostructures synthesized by existing one-step CVD technique. Transmission electron microscopy, Raman and photoluminescence mapping studies reveal that the obtained heterostructure nanosheets clearly exhibit the modulated structural and optical properties. Electrical transport studies demonstrate that the special MoS2 (monolayer)/WS2 (multilayer) heterojunctions serve as intrinsic lateral p鈥搉 diodes and unambiguously show the photovoltaic effect. On the basis of this special heterostructure, depletion-layer width and built-in potential, as well as the built-in electric field distribution, are obtained by KPFM measurement, which are the essential parameters for TMD optoelectronic devices. With further development in future studies, this growth approach is envisaged to bring about a new growth platform for two-dimensional atomic crystals and to create unprecedented architectures therefor.