Title:Recent Progress in Pyridine Containing Heterocycles as High Performance Host Materials for Blue PHOLEDs
VOLUME: 15 ISSUE: 4
Author(s):Aamer Saeed*, Muhammad Faisal, Fayaz Ali Larik*, Hesham R. El-Seedi, Pervaiz Ali Channar and Danish Shahzad
Affiliation:Department of Chemistry, Quaid-i-Azam University, Islamabad-45320, Department of Chemistry, Quaid-i-Azam University, Islamabad-45320, Department of Chemistry, Quaid-i-Azam University, Islamabad-45320, Division of Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, Biomedical Centre, Uppsala, Department of Chemistry, Quaid-i-Azam University, Islamabad-45320, Department of Chemistry, Quaid-i-Azam University, Islamabad-45320
Keywords:PHOLEDs, phosphorescent organic light-emitting diodes, host materials, blue OLED, pyridine, electron transport
material, hole transport material, carbazole, azacarbazole, organic electronics.
Abstract:Phosphorescent Organic Light-Emitting Diodes (PHOLEDs) have an advantage of stability
for a lifetime in comparison with the conventional Organic Light-Emitting Diodes (OLEDs). Green and
red OLEDs have already achieved success, but for the last decade, blue OLEDs have observed a surge
in the attention towards them from academia as well as the industry. There are incessant efforts devoted
towards the improvement of external quantum efficiency from 25-30%. The host materials (or host
compounds), hole transporting and electron transporting are the preeminent factors for the enhancement
of External Quantum Efficiency (EQE). This review aims at highlighting the role of pyridine as an efficient
Electron Transporting Material (ETM) for blue PHOLEDs. Pyridine having electron withdrawing
nature can serve as valuable host compounds for electron transport material in PHOLEDs of a blue color.
The presence of nitrogen atom in pyridine facilitates in lowering HOMO/LUMO energy levels compared
to benzene ring and this assists in adding phenyl rings at the periphery of pyridine ring.