A phosphorescent poly(dendrimer) with increased viscosity for solution-processed OLED devices

Journal article

We describe a phosphorescent green solution-processable iridium(III) complex containing poly(dendrimer), where the polymer character enhances compatibility with ink-jet printing techniques while the dendritic structure improves solid-state performance. The poly(dendrimer) shows an increased viscosity in chlorobenzene solutions of 1.1 mPa s at 25 mg/ml concentration relative to a simple first generation dendrimer. The poly(dendrimer) has a photoluminescence quantum yield of 15% in a neat film which increases to 52%, accompanied by an increase in radiative rate, when the material is blended with 4,4′-bis(N-carbazolyl)-2,2′-biphenyl (CBP). Blending with poly(styrene) results in a slightly decreased efficiency of 13%, showing the importance of choosing compatible materials when blending the poly(dendrimer). Organic light emitting diodes were fabricated containing the poly(dendrimer) and these had a 5.1% external quantum efficiency. © 2010 Elsevier B.V. All rights reserved.

Authors: Levell, J; Gunning, J; Burn, P; Robertson, J; Samuel, I

• Publication status: Published
• Journal: ORGANIC ELECTRONICS
• Volume: 11
• Issue: 9
• Pages: 1561-1568
• Publication date: 2010-09-01
• DOI: 10.1016/j.orgel.2010.05.011
• ISSN: 1566-1199
• Language: English
• Keywords: Organic semiconductor; Phosphorescence; Ink-jet printing; OLED