Two-dimensional perovskite single-crystal material and preparation method thereof

Abstract

The invention relates to a two-dimensional perovskite single-crystal and a preparation method thereof. The chemical composition of the two-dimensional perovskite single-crystal material is A2PbBr4, wherein A is C4H9NH3+ or C3H7NH3+. Lead bromide and ammonium bromide with the ratio being 1:2 are adopted as raw materials, dimethylformamide is adopted as a solvent, chlorobenzene or a mixture of chlorobenzene and acetonitrile are adopted as an anti-solvent, and due to the anti-solvent mixing evaporation method, the large-size two-dimensional perovskite single-crystal is prepared under the room temperature atmosphere environment. The method is low in environment condition requirement, simple in process, applicable to preparing large-size crystal. The two-dimensional perovskite single-crystal has the good application prospect in the photoelectric field, and the efficient and simple preparation method has the great potential for single-crystal commercialization application.

Description

technical field [0001] The invention relates to a two-dimensional perovskite single crystal and a preparation method thereof. The prepared two-dimensional single crystal has a larger crystal size. Background technique [0002] Perovskite materials have many excellent properties and are widely concerned by researchers. Perovskite solar cells are developing rapidly, and the efficiency has increased from 3.9% to more than 22%. It also has good applications in light-emitting diodes. The luminescent external quantum efficiency exceeds 14%, and it is also widely used in detectors, lasers and other fields. Perovskite single crystal, with longer diffusion length, longer lifetime has good applications, such as perovskite single crystal battery, its efficiency exceeds 18%, perovskite single crystal detector, which has a wide range of detection performance, detection of X-rays, gamma rays, visible light, etc. [0003] In recent years, the synthesis methods of perovskite single crysta...

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Problems solved by technology

The preparation of high-quality, large-sized perovskite single crystals is crucial to the preparation of high-performance devices. Common bulk organic-inorganic halide perovskite (all-inorganic perovskite) single crystals can be prepared by inverse temperature growth method , the time required is several hours, while the preparation of two-dimensional perovskite single crystals is prepared by anti-solvent evaporation-assisted method, and the preparation of large-sized two-dimensional single crystal materials takes weeks or even months, and the preparation cycle is long. Not conducive to wide application

Zhai et al. prepared (C 4 h 9 NH 3 ) 2 PbBr 4 Two-dimensional perovskite, the two-dimensional perovskite obtained by this method has more crystal nuclei, the layered structure is not obvious, and the obtained crystal size is small; Yang et al. prepared several micron-sized (C 4 h 9 NH 3 ) 2 PbBr 4 Two-dimensional perovskite flakes, the thickness of the obtained two-dimensional perovskite is relatively thin, and the crystal size is small. The crystal nuclei formed during the preparation of this method are relatively large, which is not conducive to the formation of large-sized single crystals.

Peng et al. prepared a few millimeters of PEA by cooling the crystallization method. 2 PB 4 (MAPbI 3 ) n-1 (PEA:C 6 h 5 C 2 h 4 NH 3 , n = 1, 2, 3) two-dimensional single crystal, however, this perovskite containing benzene ring in the A site is easy to decompose at room temperature, and there are certain problems in stability

[0004] Thin films are easier to prepare than single crystals, but their grain boundaries and defects are more than single crystal materials, and their application in optoelectronic devices is limited

However, the preparation of large-area, high-quality two-dimensional perovskite has a long period, which also limits its preparation efficiency.

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