Synthesis and Optoelctronic Properties of the Red Phosphorescent Host Material Containing Dibenzothiophene-S,S-dioxide

The alternating copolymer pCzFSO was prepared by using carbazole and dibenzothiophene-S,S-dioxide as the monomers. The UV-vis, photoluminescence, thermal and electrochemical properties of the polymer pCzFSO and its application as a red phosphorescent host material in an electroluminescent device were probed. The results show that the polymer pCzFSO has the thermal decomposition temperature at 426 ℃, it has the band gap at 2.77 eV and the HOMO/LUMO energy levels at −5.65 eV/−2.88 eV. The light-emitting device whose device structure is ITO/PEDOT:PSS/PVK/pCzFSO/Ba/Al comprising the polymer pCzFSO as the light-emitting layer has a maximal luminous efficiency of 0.80 cd/A and a brightness of 635 cd/m²; the phosphorescent photoelectroluminescent device with the device structure ITO/PEDOT:PSS/PVK/pCzFSO:Ir(Piq)₃/Ba/Al comprising the polymer pCzFSO as the host material has a maximal luminous efficiency of 1.62 cd/A and a luminance of 1 990 cd/m². The polymer pCzFSO is a potential red phosphorescent host material.