Phosphorescent organic light-emitting devices with in situ post-growth annealed organic layers

✍ Scribed by B.J. Chen; X.W. Sun; K.R. Sarma

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 933 KB
• Volume: 139
• Category: Article
• ISSN: 0921-5107
• DOI: 10.1016/j.mseb.2007.02.007

✦ Synopsis

A comparative study of in situ post-growth annealing of organic layers before hole-blocking layer (HBL) or metal cathode deposition was conducted on tris-(phenyl-pyridyl)-iridium complex, Ir(ppy) 3 -based phosphorescent organic light-emitting devices (PHOLED). The devices were fabricated in the same run with a standard device without annealing for comparison, with an identical structure of indium tin oxide (ITO)/copper phthalocyanine (CuPc) (10 nm)/N,N -di(naphthalene-l-yl)-N,N -diphenyl-benzidine (NPB) (90 nm)/4,4 -bis(carbazol-9yl)-biphenyl (CBP):Ir(ppy) (40 nm)/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) (15 nm)/tris(8-hydroxy-chinolinato) aluminum (Alq 3 ) (40 nm)/Mg:Ag (200 nm)/Ag (20 nm). The annealing temperature used was 60, 80 and 100 • C, before deposition of BCP HBL or before Mg:Ag cathode, respectively. It was found that, before BCP deposition, 60 • C in situ post-growth annealing improves performance of the device, and the devices decay significantly with 80 and 100 • C annealing. The in situ post-growth annealed organic layers were characterized by photoluminescence and Raman spectroscopy.