Enhancement of electrical property by oxygen doping to copper phthalocyanine in inverted top emitting organic light emitting diodes

We reported the evidence of oxygen doping to copper-phthalocyanine (CuPc) by O2-plasma treatment to inverted top-emitting organic light-emitting diodes (ITOLEDs). In situ synchrotron-radiation photoelectron spectroscopy results showed that a new Cu–O bond appeared and the energy difference between the highest-occupied molecular orbital and EF is lowered by 0.15 eV after plasma treatment. The oxygen ions chemically interacted with Cu atoms and transferred charges to the CuPc. Thus the hole injection barrier was lowered, enhancing the electroluminescent property of ITOLEDs.

[1]  T. Miyamoto,et al.  Vertical electrical conduction in pentacene polycrystalline thin films mediated by Au-induced gap states at grain boundaries , 2009 .

[2]  M. Cinchetti,et al.  Determination of spin injection and transport in a ferromagnet/organic semiconductor heterojunction by two-photon photoemission. , 2009, Nature materials.

[3]  Sung-Yoon Huh,et al.  Inverted top-emitting organic light-emitting diodes by whole device transfer , 2008 .

[4]  Wolfgang Kowalsky,et al.  Transparent Inverted Organic Light‐Emitting Diodes with a Tungsten Oxide Buffer Layer , 2008 .

[5]  Yongli Gao,et al.  Electronic structure modification of copper phthalocyanine (CuPc) induced by intensive Na doping , 2008 .

[6]  Soonmin Seo,et al.  Damage-free electrodes fabrication for top emitting organic light emitting diodes by transfer fabrication , 2007 .

[7]  Yongli Gao,et al.  Photoemission study of oxygen and Au modification of doped copper phthalocyanine , 2007 .

[8]  T. Meen,et al.  Effects of nitridation time on top-emission inverted organic light-emitting diodes , 2007 .

[9]  S. Y. Kim,et al.  Effect of magnesium oxide buffer layer on performance of inverted top-emitting organic light-emitting diodes , 2006 .

[10]  T. Nishi,et al.  Oxygen effects on the interfacial electronic structure of titanyl phthalocyanine film: p-Type doping, band bending and Fermi level alignment , 2006 .

[11]  S. Wu,et al.  A top-emission organic light-emitting diode with a silicon anode and an Sm∕Au cathode , 2004 .

[12]  G. Danev,et al.  Oxygen influence on the conductivity of copper phthalocyanine vacuum-deposited thin films , 2004 .

[13]  Chieh-Wei Chen,et al.  An effective cathode structure for inverted top-emitting organic light-emitting devices , 2004 .

[14]  J. Szuber,et al.  Photoemission study of the electronic properties of in situ prepared copper phthalocyanine (CuPc) thin films exposed to oxygen and hydrogen , 2001 .

[15]  Martin Pfeiffer,et al.  LOW VOLTAGE ORGANIC LIGHT EMITTING DIODES FEATURING DOPED PHTHALOCYANINE AS HOLE TRANSPORT MATERIAL , 1998 .

[16]  P. Siciliano,et al.  Langmuir−Blodgett Multilayers Based on Copper Phthalocyanine as Gas Sensor Materials: Active Layer−Gas Interaction Model and Conductivity Modulation , 1997 .

[17]  W. Stickle,et al.  Handbook of X-Ray Photoelectron Spectroscopy , 1992 .