Preparation method for single-layer MoS2-WS2 transverse heterojunction

Abstract

The invention discloses a preparation method for a single-layer MoS2-WS2 transverse heterojunction, which belongs to the field of nano material growth. Electrochemical oxidation treatment is carried out on selected precursor sources to volatilize the precursor sources corresponding to molybdenum and tungsten at different temperatures, and the transverse heterojunction with the micron-sized clear interface is prepared in one step by a chemical vapor deposition method. According to the method of growing the transverse heterojunction, in a tubular furnace capable of accurately controlling the temperature, inert gas is used as transport gas of reaction sources (a molybdenum source, a tungsten source and a sulfur source), and different chemical vapor deposition reactions are controlled to occurto form the transverse heterojunction. The single-layer MoS2-WS2 transverse heterojunction prepared by the method has a micron-scale clear heterojunction boundary, and the transverse size can reach 100 microns or above. According to the method, the controllability of the growth process is high, a growth temperature window can be effectively widened, the growth temperature is reduced, and size andinterface controllable growth is achieved.

Description

technical field [0001] The invention belongs to the field of nanometer material growth, and relates to the preparation of a two-dimensional transition metal chalcogen compound heterojunction. [0002] technical background [0003] In 2004, Professor Geim and Professor Novoselov used the tape mechanical stripping method to prepare single-layer graphene, thus opening the door to the field of two-dimensional materials. Graphene is an ideal two-dimensional crystal composed of a single layer of carbon atoms, with an electron mobility μ of 2×10 5 cm 2 ·V -1 ·s -1 , thermal conductivity κ≈5000W / mK is higher than diamond and graphite, elastic modulus E=1.0TPa, strength σ int =130GPa, it has broad application prospects in the construction field of micro-nano devices in the future. However, graphene, as a zero-bandgap material, is greatly limited in practical applications. molybdenum sulfide (MoS 2 ) and tungsten sulfide (WS 2 ) represented by Transitional Metal Dichalcogenides...

AI Technical Summary

Problems solved by technology

[0005] Two-dimensional material heterojunctions are mainly divided into vertical heterojunctions and lateral heterojunctions. At present, most of the theoretical and experimental researches focus on vertical two-dimensional heterojunctions. Lateral heterojunctions are required for lattice matching of heterogeneous materials. High, the experimental conditions are strict, and it is difficult to obtain high-quality samples, so there are relatively few researches on physical properties and device applications in the direction of lateral heterojunction optoelectronics

However, in these prepared lateral heterojunctions, a wide alloy region appears at the interface, and severe interface amorphization seriously affects the performance of the heterojunction.

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