Method for preparing large-area single-layer WSe2 monocrystals

Abstract

The invention discloses a method for preparing large-area single-layer WSe2 monocrystals and mainly solves the problems of complicated process and poor controllability of a traditional preparation method. The method comprises implementing steps as follows: 1, substrates are selected and subjected to RCA standard cleaning, and two substrates are selected, subjected to ultrasonic cleaning with deionized water, acetone and isopropyl alcohol in sequence for 5 min and air-blown; 2, the cleaned substrates are put in a tubular furnace, two quartz boats are prepared and taken as a W boat and an Se boat respectively, and an NaCl solution is dropwise added to the front end of the first substrate and then heated on a hot plate until deionized water is completely vaporized; WO3 is arranged on the first substrate, the first substrate is covered with the second substrate, then the W boat is placed in a high-temperature area, Se is arranged in the Se boat, and the Se boat is placed in a low-temperature area; 3, a cavity is purged, the high-temperature area and the low-temperature area of the tubular furnace are subjected to temperature control respectively, WO3 and Se are subjected to a reaction,WSe2 is produced, and a product is sealed. The method is lower in cost, high in controllability and suitable for preparing the repeatable large-area single-layer WSe2 material.

Description

technical field [0001] The invention relates to the field of microelectronic technology, in particular to a single-layer tungsten diselenide (WSe 2 ) Single crystal chemical vapor deposition (Chemical vapor deposition, CVD) preparation method for reproducible large-area single-layer WSe 2 preparation. Background technique [0002] Molybdenum disulfide (MoS 2 ), diselenide (WSe 2 ) represented by two-dimensional transition metal chalcogenide functional materials can realize the transition from indirect bandgap to direct bandgap in the process of multilayer to single layer. With its unique physical and chemical properties, it can be used in electronic devices , Optoelectronic devices and other fields have great application potential, and have received extensive attention from researchers. WS 2 The luminescence characteristics are compared with those of MoS 2 , more characteristic, currently preparing large-area single-layer WSe 2 The CVD method is mainly used, and a sel...

AI Technical Summary

Problems solved by technology

This method is representative of two-dimensional materials. In the process used, the WO is first heated 3 The powder makes it selenized at 1070°C, and finally produces WSe 2 thin film, although this method can obtain different layers of WSe 2 single crystal, but because the temperature of selenium cannot be effectively controlled independently, the grown WSe 2 The size is less than 20μm, which limits its device application

[0005] Document 3 "S.M. Eichfeld, L. Hossain, Y.-C. Lin, A.F. Piasecki, B. Kupp, A.G. Birdwell, R.A. Burke, N. Lu, X. Peng, J. Li, A. Azcatl, S. McDonnell, R.M.Wallace, M.J.Kim, T.S.Mayer, J.M.Redwing and J.A.Robinson, ACS Nano 9(2), 2080-2087(2015)." reported by W(CO) 6 For the precursor body, use (CH 3 ) 2 Se provides Se source to get WSe 2 The method is an organic vapor phase deposition method, the precursor is poisonous, requires complicated tail gas treatment and safety protection, and the cost is relatively high

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