Efficient organic light-emitting diodes with C60 buffer layer

Abstract Organic light-emitting diodes (OLEDs) with C60 buffer layer were fabricated. The effect of C60 buffer layer on the performance of the devices was investigated by inserting C60 buffer layer at the interface between the electrode and organic layers. The device structures were (1) ITO/C60 (0.0, 0.4, 0.7 and 1.0 nm)/NPB/Alq3/LiF/Al and (2) ITO/NPB/Alq3/C60 (0.0, 0.4, 0.7 and 1.0 nm)/LiF/Al. The highest brightness and efficiency of the device (1) with 0.7 nm-thick C60 layer reached 6439 cd/m2 at 16 V and 1.80 cd/A at 6.4 V, respectively. The enhancements in brightness and efficiency are attributed to an improved balance of hole and electron injections due to C60 layer blocking parts of the injected holes. On the contrary, the brightness and efficiency of the devices with the structure (2) had been hardly enhanced.

[1]  Zhenbo Deng,et al.  The effect of C60 doping on the electroluminescent performance of organic light-emitting devices , 2007 .

[2]  Sunghoon Park,et al.  Enhanced electron injection in organic light-emitting devices using Al/LiF electrodes , 2001 .

[3]  J. Kwon,et al.  The effect of C60 doping on the device performance of organic light-emitting diodes , 2005 .

[4]  Xiao Wei Sun,et al.  Field emission from modified nanocomposite carbon films prepared by filtered cathodic vacuum arc at high negative pulsed bias , 2003 .

[5]  Xiao Wei Sun,et al.  Organic light-emitting devices with in situ postgrowth annealed organic layers , 2005 .

[6]  R. Könenkamp,et al.  Determination of transport parameters in fullerene films , 1997 .

[7]  Zheng-Hong Lu,et al.  Fullerene-organic nanocomposite: A flexible material platform for organic light-emitting diodes , 2006 .

[8]  D. Bethune,et al.  Origin of dark counts in In0.53Ga0.47As∕In0.52Al0.48As avalanche photodiodes operated in Geiger mode , 2005 .

[9]  H. Tian,et al.  Cyanine dye acting both as donor and acceptor in heterojunction photovoltaic devices , 2003 .

[10]  Jean-Michel Nunzi,et al.  Efficient polymer-based interpenetrated network photovoltaic cells , 2004 .

[11]  Futao Kaneko,et al.  Organic light emitting diodes with nanostructured ultrathin layers at the interface between electron- and hole-transport layers , 2005 .

[12]  Denghui Xu,et al.  Organic light-emitting diodes with 2-(4-biphenylyl)-5(4-tert-butyl-phenyl)-1,3,4-oxadiazole layer inserted between hole-injecting and hole-transporting layers , 2010 .

[13]  Jun Yeob Lee.  Efficient hole injection in organic light-emitting diodes using C60 as a buffer layer for Al reflective anodes , 2006 .

[14]  S. T. Lee,et al.  Enhanced brightness and efficiency in organic electroluminescent devices using SiO2 buffer layers , 1999 .

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

[16]  C. Tang,et al.  Enhanced electron injection in organic electroluminescence devices using an Al/LiF electrode , 1997 .