Preparation And Properties Of Wool Keratin Passivated CsPbBr₃/MAPbBr₃ Nanocrystals

In recent years,metal halide perovskite materials have received continuous attention as a new type of optoelectronic semiconductor material.Due to its simple preparation method and excellent optoelectronic properties,it has quickly become a"star"in the field of optoelectronics.In this paper,the natural biological macromolecular material-wool keratin（WK）is used to passivate the metal halide perovskite crystal material.Wool keratin is a polymer and itself is rich in amino groups,carboxyl groups,sulfhydryl groups,amide groups,etc.,which can passivate many defects in perovskite crystal materials at the same time.Metal halide permica quantum quantum dots（PQDs）have excellent photoelectric properties such as adjustable band gaps,high-light emitting quantum yield,narrow launch peaks,etc.,but their damp and humid stability differences limited many applications.In response to the above issues,this paper proposes to use wool-horn protein to pass on to the Cs Pb Br₃ perovskite quantum point to improve its stability,and then add polyal polyxylocylocyanate（PAPI）intertwined agents to further improve the stability of quantum dots.The study found that functional groups such as amino groups,carboxyl groups and sulfhydryl groups on wool keratin can interact with Cs Pb Br₃ perovskite quantum dots to form a passivation coating.make up the structure.Compared with the unmodified Cs Pb Br₃ perovskite quantum dots,the relative luminescence intensity of wool keratin can be improved from 1 day（down to 0%）to 17 days（down to 60%）after adding cross-linking agent.On the 60th day,the quantum dots also maintained 80%of the relative photoluminescence intensity.And when the quantum dots treated with passivation are at a temperature of 120℃,the relative fluorescent strength can be maintained by more than 60%.The dampness and heat stability of the perovskite quantum dot at the above-mentioned woolen horny protein has been greatly improved.Perovskite nanocrystals polymer composites have great potential in applications such as LCD backlights and anti-counterfeiting.However,the preparation method is often complex,nanocrystals（NCs）are easy to aggregate and the solvent is mostly toxic.In view of the above problems,this paper proposes a very simple one-step process to directly use methylamine bromide（MABr）,lead bromide（Pb Br₂）and wool keratin to prepare a composite material of MAPb Br₃（MPB）NCs and WK（MPB/WK（H₂O）NCs）was prepared.On this basis,by adding ethanol（Et OH）or N,N-dimethylformamide（DMF）,MPB/WK（H₂O+Et OH）NCs and MPB/WK（H₂O+DMF）NCs with different properties can be obtained.The study found that NCs with different solvents showed different fluorescence quenching times after encountering water.The water can also be removed by heating to restore the luminescence,which is repeatable.Finally,the above composite materials were used to explore the application of information encryption and decryption.In addition,inorganic hole transport materials are an important direction for the preparation of low-cost and stable perovskite batteries.Wool keratin combined with cuprous iodide（Cu I）as a hole transport layer is beneficial to the use of wool keratin to improve Cu I film formation and passivation.Preliminary research on the perovskite light absorption layer was carried out,and a beneficial attempt was made for the further preparation of high-efficiency and low-cost perovskite solar cells based on the Cu I inorganic hole transport layer.