Self-assembly surface modified indium-tin oxide anodes for single-layer light-emitting diodes based on polyfluorene blends

We study the effect of indium-tin oxide surface modification by self assembling of highly polar molecules on the performance of single-layer light-emitting diodes (LEDs) fabricated with polyfluorene blends and aluminium cathodes. We find that the efficiency and light-output of such LEDs is comparable to, and sometimes better than, the values obtained for LEDs incorporating a hole injection layer of poly(3,4-ethylene dioxythiophene) doped with polystyrene sulphonic acid. This effect is attributed to the dipole-induced work function modification of indium-tin oxide.

[1]  F. Cacialli,et al.  Tuning the optoelectronic properties of polyfluorenes by copolymerisation with thiophene moieties , 2002 .

[2]  J. Reynolds,et al.  Poly(3,4‐ethylenedioxythiophene) and Its Derivatives: Past, Present, and Future , 2000 .

[3]  Donal D. C. Bradley,et al.  Quantifying the efficiency of electrodes for positive carrier injection into poly(9,9-dioctylfluorene) and representative copolymers , 2001 .

[4]  Alan J. Heeger,et al.  Polymer light-emitting diodes with polyethylene dioxythiophene–polystyrene sulfonate as the transparent anode , 1997 .

[5]  D. Bradley,et al.  Energy transfer dynamics in polyfluorene-based polymer blends , 2001 .

[6]  Zhiqiang Gao,et al.  Blocking reactions between indium-tin oxide and poly (3,4-ethylene dioxythiophene):poly(styrene sulphonate) with a self-assembly monolayer , 2002 .

[7]  Jorge Morgado,et al.  De‐mixing of Polyfluorene‐Based Blends by Contact with Acetone: Electro‐ and Photo‐luminescence Probes , 2001 .

[8]  H. Bässler,et al.  Tandem injection of charge carriers across a metal-dielectric interface , 2000 .

[9]  Udo Bach,et al.  Modification of TiO2 heterojunctions with benzoic acid derivatives in hybrid molecular solid-state devices , 2000 .

[10]  Franco Cacialli,et al.  Efficient electron injection in blue-emitting polymer light-emitting diodes with LiF/Ca/Al cathodes , 2001 .

[11]  Donal D. C. Bradley,et al.  Nondispersive hole transport in an electroluminescent polyfluorene , 1998 .

[12]  Franco Cacialli,et al.  Molecular-scale interface engineering for polymer light-emitting diodes , 2000, Nature.

[13]  Donal D. C. Bradley,et al.  Dispersive electron transport in an electroluminescent polyfluorene copolymer measured by the current integration time-of-flight method , 2001 .

[14]  F. Cacialli,et al.  Excitation energy transfer and spatial exciton confinement in polyfluorene blends for application in light-emitting diodes , 2002 .

[15]  Masamichi Fujihira,et al.  Fine tuning work function of indium tin oxide by surface molecular design: Enhanced hole injection in organic electroluminescent devices , 2001 .

[16]  Richard L. Martin,et al.  CONTROLLING CHARGE INJECTION IN ORGANIC ELECTRONIC DEVICES USING SELF-ASSEMBLED MONOLAYERS , 1997 .

[17]  R. N. Marks,et al.  Light-emitting diodes based on conjugated polymers , 1990, Nature.

[18]  W. R. Salaneck,et al.  Kelvin probe and ultraviolet photoemission measurements of indium tin oxide work function: a comparison , 2000 .

[19]  R. Friend,et al.  Built-in field electroabsorption spectroscopy of polymer light-emitting diodes incorporating a doped poly(3,4-ethylene dioxythiophene) hole injection layer , 1999 .

[20]  A. Shanzer,et al.  Molecular control over Au/GaAs diodes , 2000, Nature.

[21]  Martin R. Willis,et al.  Organic electroluminescent devices: enhanced carrier injection using SAM derivatized ITO electrodes , 2000 .

[22]  M.J.A. de Voigt,et al.  Stability of the interface between indium-tin-oxide and poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) in polymer light-emitting diodes , 2000 .

[23]  Jerzy Kanicki,et al.  High performance organic polymer light-emitting heterostructure devices , 1999 .

[24]  James J. O'Brien,et al.  Progress with Light‐Emitting Polymers , 2000 .

[25]  W. R. Salaneck,et al.  Polymer band alignment at the interface with indium tin oxide: consequences for light emitting devices , 1999 .

[26]  Jorge Morgado,et al.  Reduction of the light-onset voltage of light-emitting diodes based on a soluble poly(p-phenylene vinylene) by grafting polar molecules onto indium–tin oxide , 2002 .

[27]  F. Cacialli,et al.  Energy level line-up in polymer light-emitting diodes via electroabsorption spectroscopy , 2001 .

[28]  W. R. Salaneck,et al.  Electroluminescence in conjugated polymers , 1999, Nature.