Regulation Of Organic Gelators And Ionic Liquids In The Performance Of Luminescent Materials

The regulation of the performance of luminescent materials is critical for their application in the opto-electronic devices.Non-covalent interactions between molecules strongly affected the performance of luminescent materials,and the study on its mechanism has great significance for the development of optoelectronic devices with high efficiencies.This thesis aims to investigate the regulation mechanism of the performance of luminescent materials by the non-covalent interactions between molecules.D-gluconic acid derivated gelators and ionic liquids（ILs）are utilized in the preparation of circularly polarized luminescent（CPL）materials and perovskite quantum dots（QDs）.The influence of supramolecular assemblies’structures on the CPL properties of the materials,as well as the correlation between gelator and hybrid of ILs and the optical performance of blue emitting Cs Pb Br₃ QDs,have been explored.（1）Two novel tetraphenylethylene（TPE）derivatives（denoted as A12-TPE and T12-TPE）were prepared by incorporating different chiral D-gluconic acid substituents into the TPE core.Their self-assembly structures and CPL performance were then investigated.Due to the synergy effect of steric hindrance of the acetal group and chiral induction of D-gluconic acid part,A12-TPE possesses a helical supermolecular structure,which endowed the material with distinct CPL properties.On the contrary,T12-TPE without the acetal group exhibits a lamellar structure rather than a helical structure,and no CPL signal can be observed.（2）The preparation method of blue-emitting Cs Pb Br₃ QDs has been optimized,and the influence between organic gelator and luminescent performance of Cs Pb Br₃QDs has been explored.Gelator G16 was used in the preparation of Cs Pb Br₃ QDs,and the precipitation process of QDs can be controlled by the fibril networks which was formed by self-assemble of the gelator.Hydrogen bonding between molecules and hydrophobic interactions also existed between gelator and QDs.Therefore,photoluminescent（PL）intensity of gelator-assisted QDs was enhanced to 3.21 times that of the QDs without the addition of gelator.（3）Besides,ILs were also added to Cs Pb Br₃ QDs to improve their PL intensities and stabilities.Though the reasonable screening of ILs,the PL intensities and stabilities of QDs have been effectively enhanced.With the addition of ILs,the photoluminescence quantum yields of blue-emitting Cs Pb Br₃ QDs increased from 33.8%to～50%.The main reason for the enhancement in optical performance is that ILs formed effective passivation on QDs with surface Pb²⁺.On the other hand,the UV irradiation stabilities and storage stabilities of QDs are enhanced by the hydrophobicity which is originated from alkyl chain of ILs.And QDs with longer alkyl chain ILs exhibit better stabilities than the ones with shorter alkyl chain ILs.