Increased efficiency in vertically segregated thin-film conjugated polymer blends for light-emitting diodes

The effect of film morphology on the performance of conjugated polymer-blend light-emitting diodes (LEDs) has been investigated. Vertically segregated structures have been fabricated by varying the spinning conditions and solvents used so that phase separation normal to the substrate is induced. External quantum efficiencies show that LEDs made with vertically segregated structures are between 25% and 100% more efficient than laterally segregated LEDs, depending on the scale of lateral phase separation.

[1]  R. Friend,et al.  ESEM imaging of polyfluorene blend cross-sections for organic devices , 2002 .

[2]  Yang Yang,et al.  Efficient polymer light-emitting diodes using conjugated polymer blends , 2002 .

[3]  Richard H. Friend,et al.  Vertically segregated polymer-blend photovoltaic thin-film structures through surface-mediated solution processing , 2002 .

[4]  Yang Yang,et al.  High Performance Polymer Light-Emitting Diodes Fabricated by a Low Temperature Lamination Process** , 2001 .

[5]  A. Arias,et al.  Raman microscopy determination of phase composition in polyfluorene composites , 2001 .

[6]  Jeremy Burroughes,et al.  Very‐high‐brightness diodes for passive‐matrix display applications , 2001 .

[7]  Richard H. Friend,et al.  Photovoltaic Performance and Morphology of Polyfluorene Blends: A Combined Microscopic and Photovoltaic Investigation , 2001 .

[8]  Richard H. Friend,et al.  Electroluminescence emission pattern of organic light-emitting diodes: Implications for device efficiency calculations , 2000 .

[9]  David G Lidzey,et al.  Bright and efficient blue and green light-emitting diodes based on conjugated polymer blends , 2000 .

[10]  Richard H. Friend,et al.  Photodiodes Based on Polyfluorene Composites: Influence of Morphology , 2000 .

[11]  B. S. Chuah,et al.  Light-emitting devices based on a poly(p-phenylene vinylene) derivative with ion-coordinating side groups , 1999 .

[12]  Richard H. Friend,et al.  CHARGE- AND ENERGY-TRANSFER PROCESSES AT POLYMER/POLYMER INTERFACES : A JOINT EXPERIMENTAL AND THEORETICAL STUDY , 1999 .

[13]  Yong Cao,et al.  Improved quantum efficiency for electroluminescence in semiconducting polymers , 1999, Nature.

[14]  Mats Andersson,et al.  Laminated fabrication of polymeric photovoltaic diodes , 1998, Nature.

[15]  Richard H. Friend,et al.  An improved experimental determination of external photoluminescence quantum efficiency , 1997 .

[16]  C. A. Walsh,et al.  Efficient photodiodes from interpenetrating polymer networks , 1995, Nature.

[17]  Alan J. Heeger,et al.  Enhanced electroluminescence from semiconducting polymer blends , 1995 .

[18]  R. H. Friend,et al.  Efficient light-emitting diodes based on polymers with high electron affinities , 1993, Nature.

[19]  C. Tang,et al.  Organic Electroluminescent Diodes , 1987 .

[20]  C. Tang.  Two‐layer organic photovoltaic cell , 1986 .