Phosphorescent organic light-emitting diodes PhOLEDs

The phosphorescent organic light emitting diodes (PHOLEDs) based on Ir(dmp>py)3 complexes were fabricated by the vacuum deposition technique with the following configuration ITO/copper phthalocyanine (CuPc, 10 nm) as hole injection layer/4,4 -bis[(l-naphthyl)(phenyl)-amino]-l,l -biphenyl (NPD, 40 nm) as hole transport layer/CBP Ir(dmppy)3 (8%) (20 nm) as emissive layer/2,9-dimethyl-4,7-diphenyl-l,10-phenanthroline (BCP, 10 nm) as a hole blocking layer/ tris-(8-hydroxyquinoline)aluminum (Alqs, 40 nm) as an electron transport layer/LiF (1 nm) as electron injection layer/ A1 (100... 

An important breakthrough came with the discovery that with the addition of phosphorescent dopant emitters such as Ft, Ir, Os, etc., the energy could be transferred from the triplet states to the dopant molecules which could decay radiatively. As a result, the internal quantum efficiency (the number of photons generated inside the device per electron-hole pair injected) of these phosphorescent organic light-emitting diodes (PHO-LEDs) (PHOLED is a trademark of the Universal Display Corporation, Ewing, New Jersey) can approach a quantum efficiency 100% at a luminescence of 100 cd/sr. 

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