Preparation method of molybdenum disulfide/tungsten diselenide vertical heterojunction

Abstract

The invention relates to a preparation method of a molybdenum disulfide / tungsten diselenide vertical heterojunction. The method comprises: first preparing a molybdenum disulfide thin layer by chemical vapor deposition on a silicon dioxide / silicon substrate, and then directly depositing a tungsten diselenide thin layer on the above substrate by chemical vapor deposition again, and With the assistance of NaI, the vertical heterojunction formed by the two materials is realized at a growth temperature of 600-700°C. The preparation method of the molybdenum disulfide / tungsten diselenide vertical heterojunction material of the present invention has a simple process, and the low melting point salt is added to the raw material and combined with a mature basic process, which can avoid the atomic replacement and heat loss of the underlying transition metal disulfides (TMDCs). Unfavorable factors such as decomposition and alloying can be eliminated to realize the growth of two-dimensional heterojunctions with high quality and atomically steep interfaces. The invention proposes a new growth mechanism, which can further understand the growth process of TMDCs vertical heterojunction in terms of nucleation and kinetics, and defines a multifunctional material platform for basic research and potential device applications.

Description

technical field [0001] The invention relates to the field of heterojunction preparation of two-dimensional materials, in particular to a method for preparing a vertical heterojunction of molybdenum disulfide / tungsten diselenide at low temperature. Background technique [0002] With molybdenum disulfide (MoS 2 ), tungsten diselenide (WSe 2 ) and other two-dimensional materials controllable synthesis technology, its excellent performance has attracted the attention of many researchers. A single type of two-dimensional material exhibits some unique physical properties. For example, a single layer of molybdenum disulfide is a semiconductor material with a direct band gap. and applications in optoelectronic devices; however, a single material also has its own limitations, such as a single band gap energy, limited light absorption efficiency, and optoelectronic properties limited by the conductive properties of a single material, etc., which also limit its application. Studies ...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a preparation method of molybdenum disulfide / tungsten diselenide vertical heterojunction at low temperature, which solves the problems of uncontrollable epitaxial growth direction, thermal decomposition and alloying in the growth process of heterojunction materials, so as to realize Controlled growth of high-quality vertical two-dimensional heterojunctions

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