Design,Synthesis And Photoelectric Properties Of Deep Blue Organic Materials

At present,blue light materials mainly face the following problems.At first,the wide forbidden band is not conducive to carrier injection and transmission.Then the aggregation effect causes red shift of light color and short conjugate length leads to limited building groups.It is still a challenge to fabricate deep blue organic luminescence materials with efficiency and chromaticity.In view of the above key scientific issues.By adopting the donor-acceptor type fluorescent material,from the perspective of material chemistry,the types and strengths of the acceptor groups are regulated,and a series of deep blue organic light-emitting molecules are constructed to further study the molecular structure of the photophysical and electroluminescent devices,which providing the idea for designing high-efficiency,high-color purity deep blue organic luminescent molecules.Specific research contents are as follows:1.Using phenothiazine as electron donor and phenamimidazole and oxadiazole as electron acceptors,two novel electron donating acceptor fluorescent molecules(TPEPPI and TPEPO)were designed and synthesized.The relationship between the acceptor structure and the properties of photophysical and electroluminescent devices was systematically investigated.The difference in the torsion angle between the donor and acceptor resulted in a significant aggregation-induced luminescence(AIE)phenomenon observed only in TPEPPI,whereas only solvation occurred in TPEPO;The electron transport difference of the acceptor group makes the device III based on TPEPO as the light-emitting layer have better maximum current efficiency and maximum power efficiency than TPEPPI-based device I.The main reason is that the electron transport property of oxadiazole is superior to that of phenanthrene,which enables balanced transport of carriers.2.Using 1,2,4-triazole as electron donor group,triphenylamine,anthracene and 3,6-di-tert-butylphenylcarzole as electron acceptor groups,three novel electron donor-acceptor fluorophors(ANTZ,TPATZ and DTPCZTZ)were designed and synthesized,and the effects of differences in donor groups on material properties were investigated.The electron donating ability of triphenylamine,3,6-di-tert-butylphenylcarzole and anthracene gradually weakened,but the conjugation length was opposite,and considering the difference of the conjugated bridge,the order of the electroluminescence emission peak from long wavelength to short wavelength is ANTZ>TPATZ>DTPCZTZ.The external quantum efficiency of the undoped device based on TPATZ reaches 5.92%,CIE of(0.155,0.047),and the external quantum efficiency of the undoped device based on DTPCZTZ up to 4.48%,CIE of(0.162,0.037),which belongs to high efficiency devices with satisfactory color purity.