Electroluminescence enhancement in blue phosphorescent organic light-emitting diodes based on different hosts

• 来源期刊: 光电子快报（英文版）
• 年，卷（期）: 2013,（5）
• 页码范围: 346-349
• 页数: 4页
• 语种: 英文
• DOI: 10.1007/s11801-013-3113-4

摘要

Blue phosphorescent organic light-emitting diodes (OLEDs) are fabricated by utilizing the hole transport-type host material of 1,3-bis(carbazol-9-yl)benzene (MCP) combined with the electron transport-type host material of 1,3-bis(triphenylsilyl)benzene (UGH3) with the ratios of 1(∶)0,8(∶)2 and 6(∶)4,and doping with blue phosphorescent dopant of bis(4,6-difluorophenylpyridinato-N,C2)picolinatoiridium (FIrpic).The device with an optimum concentration proportion of MCP(∶)UGH3 of 8(∶)2 exhibits the maximum current efficiency of 19.18 cd/A at luminance of 35.71 cd/m2 with maintaining Commission Intemationale de L'Eclairage (CIE) coordinates of(0.1481,0.2695),which is enhanced by 35.7％ compared with that of 1(∶)0 with (0.1498,0.2738).The improvements are attributed to the effective carrier injection and transport in emitting layer (EML) because of mixed host materials.In addition,electron and exciton are confined in the EML,and 4,4',4"-Tris(carbazol-9-yl)-triphenylamine (TCTA) and Di-[4-(N,N-ditolyl-amino)-phenyl]cyclohexane (TAPC) have the high lowest unoccupied molecular orbital (LUMO) energy level and triplet exiton energy.