A method for preparing and transferring ultrathin large size lead iodide nanosheets

Abstract

The invention discloses a method for preparing and transferring ultra-thin and large-sized lead iodide nanosheets. The method comprises uniformly mixing pure lead iodide powder and ultrapure water according to a certain proportion, heating and stirring at a certain temperature, and then using The solution method is to drop a certain volume of solution on a substrate with a metal coating on the surface at a certain temperature to prepare ultra-thin lead iodide nanosheets; use the characteristics of growing lead iodide nanosheets on the liquid surface to drain or orient them Transfer to the target substrate or sample, non-destructive ultra-clean transfer of ultra-thin large-sized lead iodide nanosheets can be achieved. The invention can prepare and transfer ultra-thin and large-size lead iodide nanosheets with a size of 50-200um, a thickness of 3-20nm, a single crystal structure and high quality, and has important reference significance for growing more nanosheets based on solution method. Physical mechanisms such as molecular dynamics can be further studied, and the transfer method provided by the present invention has the advantages of non-destructive ultra-cleaning, good controllability, high repeatability, high yield, low cost, etc., and is beneficial to industrial production.

Description

technical field [0001] The invention relates to a method for preparing and transferring ultra-thin large-size lead iodide nanosheets. The method is simple in preparation, low in cost, good in repeatability and high in yield, and is helpful for further research on physical mechanisms such as molecular dynamics, and has Conducive to industrial production. Background technique [0002] In recent years, two-dimensional materials have attracted extensive attention in the materials field due to their unique quantum confinement size. Ultrathin two-dimensional nanomaterials are an emerging class of nanomaterials with sheet-like structures with horizontal dimensions exceeding 100 nm or several micrometers or even larger, but only a single or a few atoms thick (typically less than 5 nm thick). Since graphene (graphite with a thickness of one atomic layer) was prepared, its novel chemical and physical properties have attracted the research enthusiasm and interest of many scientists an...

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Problems solved by technology

[0004] However, the preparation method of two-dimensional lead iodide nanosheets still needs further improvement

At present, the methods for synthesizing lead iodide crystals with various nanosheet structures mainly include: mechanical exfoliation method, physical vapor deposition method and solution method. However, PbI prepared by mechanical exfoliation method 2 Difficult to exfoliate large, uniform thin layers of material with poor reproducibility and irregular shapes

The physical vapor deposition method can prepare a single layer of PbI with smooth surface and regular shape. 2 nanosheets, but the implementation of this method needs to be carried out under high temperature conditions and a vacuum environment, and the operation is more complicated and difficult to control

Preparation of PbI by conventional solution method 2 Nanosheets also have flat surfaces and regular shapes, but the size and thickness of the grown nanosheets do not have strong regularity, making it difficult to prepare ultra-thin and large-sized PbI 2 Nanosheets

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