Synthesis Of Blue Oled Materials Through The Way Of Metal Assisted Delayed Fluorescent

Nowadays,the organic light emitting diodes(OLEDs)materials are mainly focused on the second generation phosphorescent materials and the third generation TADF luminescent materials.They promise the great prospect of application because of their internal quantum efficiencies can reach 100%.However,the poor stability of high efficiency blue phosphorescent materials limits its practical applications.Furthermore,for TADF emitters,a small ?EST and a high radiative transition rate of singlet states are always difficult to obtain at once.Therefore,we report an efficient approach called metal assisted delayed fluorescent(MADF)to ensure both efficient phosphorescence via heavy-atom effect and delayed fluorescent processes.And for that,a MADF material based on TADF parts with carbazole donor,triazine derivatives acceptor and phosphorescent covenlented to FIrpic was designed.TADF part acts as a host material for FIrpic in MADF materials.On one hand,the concentration quenching effect of the MADF materials can be effectively restrained through encapsulating the metal core by TADF units.And thus the luminescence efficiency of MADF material can be improved.On the other hand,the part of TADF has a high triplet energy level,which can ensure that energy transferred from TADF part to Ir complex part.The decay curve of target product shows two different kinds of photoluminescencent photons,which decay times are 0.29 ?s and 0.89 ?s for 48.7%and 51.3%respectively.It indicteds the material has both phosphorescence and delayed fluorescence properties.UV-Vis absorption spectra displays the energy gap is 3.18 eV.PL spectra exhibits that it's a blue light-emitting material and it has a high triplet energy level(ET = 2.74 eV).All these indicate that the target product is a potential high efficiency blue OLED material.