Oxygen-Plasma-Treated Indium–Tin-Oxide Films on Nonalkali Glass Deposited by Super Density Arc Plasma Ion Plating

The effects of O2 plasma treatment on both the chemical composition and work function of an indium–tin-oxide (ITO) film were investigated. ITO films were deposited on non-alkali glass substrate by super density arc plasma ion plating for application in active-matrix organic light-emitting diodes (OLEDs). The water contact angle decreased from 38 to 11° as the ITO films were treated with O2 plasma for 60 s at a plasma power of 150 W, indicating an increase in the hydrophilicity of the surface. It was found that there were no distinct changes in the microstructure or electrical properties of the ITO films with O2 plasma treatment. Synchrotron radiation photoemission spectroscopy data revealed that O2 plasma treatment decreased the amount of carbon contamination and increased the number of unscreened states of In3+ and (O2)2- peroxo species. This played the role of increasing the work function of the ITO films by 1.7 eV. As a result, the turn-on voltage of the OLED decreased markedly from 24 to 8 V and the maximum luminance value of the OLED increased to 2500 cd/m2.

[1]  Kenji Ebihara,et al.  Enhanced performance of the OLED with plasma treated ITO and plasma polymerized thiophene buffer layer , 2007 .

[2]  Chih-Lung Lin,et al.  A Novel Voltage Driving Method Using 3-TFT Pixel Circuit for AMOLED , 2007, IEEE Electron Device Letters.

[3]  T. Voorhis,et al.  Extrafluorescent electroluminescence in organic light-emitting devices. , 2007, Nature materials.

[4]  H. Baik,et al.  Surface cleaning of indium tin oxide by atmospheric air plasma treatment with the steady-state airflow for organic light emitting diodes , 2007 .

[5]  Yanfeng Dai,et al.  Improved performances of organic light-emitting diodes with metal oxide as anode buffer , 2007 .

[6]  G. Yeom,et al.  Study on the O2 Plasma Treatment of Indium Tin Oxide for Organic Light Emitting Diodes Using Inductively Coupled Plasma , 2006 .

[7]  Y. Yoon,et al.  Study on work function change of ITO modified by using a self-assembled monolayer for organic based devices , 2006 .

[8]  Huasong Peng,et al.  Indium tin oxide thin films by bias magnetron rf sputtering for heterojunction solar cells application , 2005 .

[9]  S. Y. Kim,et al.  High-performance organic light emitting diodes fabricated with a ruthenium oxide hole injection layer , 2005 .

[10]  M. Leu,et al.  Effect of substrate angle on properties of ITO films deposited by cathodic arc ion plating with In–Sn alloy target , 2005 .

[11]  M. Leu,et al.  Deposition of indium tin oxide thin films by cathodic arc ion plating , 2005 .

[12]  Ki-Beom Kim,et al.  Effect of ultraviolet-ozone treatment of indium-tin-oxide on electrical properties of organic light emitting diodes , 2004 .

[13]  H. Ishida,et al.  Static and quasistatic response of Ag surfaces to a uniform electric field , 2002 .

[14]  H. Jain,et al.  New evidence for the point defect model of ion transport in glasses , 2002 .

[15]  K. Kondo,et al.  Deposition of low-resistivity ITO on plastic substrates by DC arc-discharge ion plating , 2002 .

[16]  G. Franz,et al.  Characterization of sputtered indium tin oxide layers as transparent contact material , 2001 .

[17]  P. Thilakan,et al.  Investigations on the crystallisation properties of RF magnetron sputtered indium tin oxide thin films , 2001 .

[18]  R. Egdell,et al.  High resolution x-ray photoemission study of plasma oxidation of indium–tin–oxide thin film surfaces , 2000 .

[19]  Hoi Wai Choi,et al.  Plasma-induced damage to n-type GaN , 2000 .

[20]  D. Milliron,et al.  Surface oxidation activates indium tin oxide for hole injection , 2000 .

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

[22]  S. Mikoshiba,et al.  Formation of Current Leakage Paths at the Interface between Dielectrics in Intense Electric Fields in a Gas Discharge Display Device , 1991 .