Research On Preparation And Application Of Chiral Semiconductor Nanomaterials

Circularly polarized luminescence(CPL)materials have broaden application prospects in the fields of 3D display,data storage,chiral sensing,optically active materials,supramolecular chiral control,and asymmetric catalysis.Because of the advantages of simple synthesis,abundant materials,adjustable morphology,high fluorescence quantum yield,and narrow emission peak width,it is of great significance to study the CPL properties of inorganic nanomaterials.However,the reported inorganic CPL materials generally have the problem of low luminescence dissymmetry factor(g_lum=10^-5-10^-3),which is far from practical applications.Therefore,it is of great significance to study the use of simple and effective methods to construct inorganic CPL materials with high g_lum value.In this paper,chiral inorganic nanomaterials are designed and constructed based on the two chiral acquisition methods of chiral ligand induction and symmetry breaking co-assembly.The specific contents are as follows:R/S-2-Aminooctane is used as a chiral ligand to induce CsPbBr₃ perovskite nanocrystals to generate chirality and obtain CPL.The absorption dissymmetry factor g_abs=2.0×10^-4 and g_lum=1.1×10^-3.After embedding upconversion nanoparticles(UCNP)into chiral perovskite nanocrystals(PKNC),UCNP-loaded chiral perovskite nanocrystals(UCNP@PKNC)can be obtained,realizing upconverted CPL(UC-CPL)and energy transfer enhanced CPL.In the UCNP@PKNC system,based on the induction of chiral CsPbBr₃ nanocrystals,UCNP has CPL activity through spatial chiral transfer.Chiral PKNC can reabsorb the chiral energy produced by chiral UCNP,showing energy transfer enhanced CPL.The g_lum=4.5×10^-3 of UC-CPL is four times stronger than g_lum=1.1×10^-3 of PKNC.This provides a new and meaningful strategy for designing inorganic CPL active materials with high g_lum.The achiral gel factor was selected as the chiral source,and two inorganic achiral UCNPs were used as luminous bodies.Chiral transmission between gel factor and UCNP is achieved through symmetry breaking co-assembly,which induces UCNP chiral luminescence.Without adding any chiral additives,chiral inorganic luminescent nanomaterials were obtained,and the UC-CPL signal had a g_lum value on the order of10^-2.At the same time,the chiral supramolecular assemblies obtained by using the vortex-accompany assembly method(VAA)can be used as"chiral seeds",and these"chiral seeds"can further control the chirality of the co-assembly in the subsequent VAA process.The signal direction of UC-CPL can be regulated by the signal direction of"chiral seeds".The positive"chiral seed"regulated co-assembly has a positive g_lumvalue,the negative"chiral seed"regulated co-assembly has a negative g_lum value,and this regulation has certain repeatability.