Synthesis And Photo-and Electro-luminescent Properties Of Oganic Molecule Attached To POSS/Quantum Dots Materials

Organic electroluminescent devices(OLEDs)have a fast response,low cost,and high brightness compared with traditional light emitter.In the field of display,OLEDs has excellent potential of development.and its low power consumption become a leader in the field of display.In OLEDs,according to the different organic light-emitting materials can be divided into two kinds.fluorescent and phosphorescent OLEDs.As the phosphorescent material can use the triplet energy level,so the phosphorescent material internal quantum efficiency is far greater than the fluorescent material,theoretically can reach 100%.According to the study,it was found that the phosphorescent devices prepared by the transition metal iridium(Ir)complex were more efficient thanprepared by other metal complexes.In organic light-emitting materials,due to the accumulation of organic molecules,there is aggregation between the molecules induced quenching effect,which will have a great impact on the luminous performance of OLEDs.Polyhedral oligomeric silsesquioxane(POSS),is a cage-like rigid inorganicorganic hybrid nano-materials.in the luminescent material,the luminous group grafted on POSScan effectively reduce the ACQ effect.Quantum dots have excellent optical properties.Compared with traditional organic fluorescent dyes,quantum dots have wide excitation wavelengths,narrow emission wavelengths,emission wavelengths can be controlled by controlling the size of quantum dots,good light stability,anti-bleaching ability and many other advantages.Therefore,quantum dots are widely used in light-emitting diodes(Q-LED),solar cells,biological fluorescence recognition and so on.The blue organic fluorescent material grafted on the orange light quantum dots can be prepared by a new organic-inorganic hybrid warm white light-emitting material.In this article,we synthesized two phosphorescent complexes Ir(L)2(Cz-acac-allyl)and Ir(nbt)2(Cz-acac-allyl).Then,the two complexes were grafted onto the POSS core by hydrosilylation,we obtained three green POSS hybrid luminescent materials,7Cz-Ir(L)2(Cz-acac)-POSS(POSS-1),6Cz-2Ir(L)2(Cz-acac)-POSS(POSS-2),5Cz-3Ir(L)2(Cz-acac)-POSS(POSS-3)and a red POSS hybrid luminescent material,7Cz-Ir(nbt)2(Cz-acac)-POSS(POSS-4).POSS has high thermal stability and strong rigidity,the organic luminescence group grafted on the POSS,not only can improve the physical and chemical stability,but also very effective to avoid the aggregation induced quenching effect.At the same time,POSS can react with organic molecules with multiple active sites,so different organic functional molecules can be grafted onto POSS to get efficient luminescent materials.We also synthesized CdSe quantum dots with orange light and 7-((10-mercaptodecyl)oxy)-3-(pyridin-2-yl)-2H-chromen-2-one(Coumarin-SH)with blue fluorescence.Through the way of ligand exchange,obtained a new warm white material(Coumarin-SH @ CdSe).This paper is divided into five chapters,the first chapter introduced the basic theoretical knowledge of the organic light-emitting diode and quantum dots,In the second chapter,the synthesis method and device characterization of the green complex Ir(L)2(Cz-acac-allyl)and green POSS hybrid luminescent materials are introduced in detail In the third chapter,the synthesis methods and device characterization of red light complex Ir(nbt)2(Cz-acac-allyl)and red light POSS hybrid luminescent materials are introduced in detail,,and the problems in the course of the experiment were discussed.In the fourth chapter,the synthesis method and photo-electric properties of a new type of coumarin-SH were studied and grafted on orange CdSe quantum dots.