Efficient Polymer Red Light-emitting Diodes with Cathode Interface Modification Layer Based on Phosphonate Polyfluorene

Abstract

Abstract: This work presents the fabrication of efficient red polymer light-emitting diodes by spin coating the alcohol-soluble poly(9,9-bis(6′-diethoxylphosphorylhexyl)fluorene)(PF-EP) onto the surface of the electroluminescent film before the device cathode, made of Al, rather than the low work function metals, such as Ca or Ba, is deposited. By the high-resolution XPS, the interaction of thermally evaporated Al with the PF-EP layer was investigated. The efficiency of PLEDs with an organic oxide/Al composite cathode, reaches 7.0 cd/A, which is markedly higher than the efficiency of 4.0 cd/A of device with Ca/Al cathode. The light-emitting efficiency is increased by 75%. It may provide a way to improve the device performance of polymeric phosphorescent diodes.

Key words: Polymer light-emitting diode, Polyfluorene, Phosphonate

TrendMD:

NIU Xiao-Di, LIU Jing-Bo, WANG Song, WANG Hong-Su*, NIAN Gui-Jun*. Efficient Polymer Red Light-emitting Diodes with Cathode Interface Modification Layer Based on Phosphonate Polyfluorene[J]. Chem. J. Chinese Universities, 2010, 31(9): 1874.

References

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