The photoluminescence, i.e., fluorescence and phosphorescence, characteristics of host materials with wide energy gaps suitable for phosphorescence-based organic light-emitting diodes (OLEDs) are summarized. In the vacuum deposited films, the host materials show phosphorescent emission in the blue to green region and triplet energy levels of ET = 2.6-3.1 eV because of the presence of steric hindrance. An OLED containing 1,2,3,4-tetraphenyl-5-(3-pyridyl)benzene as a host and iridium(III) bis[(4,6-difluorophenyl)-pyridinato-N,C2]picolinate as a blue emissive phosphorescent dopant exhibits an external electroluminescence efficiency of ∼12%.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)