Production of dispersions with small particle size from commercial indium tin oxide powder for the deposition of highly conductive and transparent films

Abstract Indium tin oxide (ITO) nanoparticle films for applications in printable electronics were prepared by dip-coating. The dispersion conditions (bead size, stabilizer concentration) strongly affect the particle size of the ITO suspensions and consequently determine the surface morphology of the ITO films. Deposition from ethanolic ITO suspensions with an extremely small particle size of 17 nm to 21 nm led to the formation of extremely smooth and spike-free ITO films with a typical root mean square surface roughness of 4.5 nm ± 0.2 nm and a high optical transparency above 95%. The effect of annealing with forming gas and CO 2 laser treatment on the electrical properties of the ITO films was investigated. Annealing with forming gas and CO 2 laser treatment led to a temporary increase in the electrical conductivity of the ITO films by up to a factor of 10 and 6, respectively. Specific conductivities of up to 196 S cm − 1 were obtained for our ITO nanoparticle films under optimized conditions.

[1]  G. Goerigk,et al.  Microstructure formation in dip-coated particulate films. , 2006, Journal of colloid and interface science.

[2]  Shang-Chou Chang,et al.  Annealing effect of ITO and ITO/Cu transparent conductive films in low pressure hydrogen atmosphere , 2006 .

[3]  W. Peukert,et al.  The influence of dispersing and stabilizing of indium tin oxide nanoparticles upon the characteristic properties of thin films , 2009 .

[4]  J. Pinel,et al.  Excimer laser beam/ITO interaction: from laser processing to surface reaction , 2008 .

[5]  Seung‐Man Yang,et al.  Colloidal indium tin oxide nanoparticles for transparent and conductive films , 2006 .

[6]  A. Kwade,et al.  Efficiency of different dispersing devices for dispersing nanosized silica and alumina , 2011 .

[7]  M. Aegerter,et al.  Direct gravure printing of indium tin oxide nanoparticle patterns on polymer foils , 2008 .

[8]  P. Wellmann,et al.  Conductance Enhancement Mechanisms of Printable Nanoparticulate Indium Tin Oxide (ITO) Layers for Application in Organic Electronic Devices , 2009 .

[9]  H. Hoffmann,et al.  Optical and Electrical Properties of RF-Sputtered Indium-Tin Oxide Films , 1983, June 16.

[10]  Hee K. Park,et al.  Fiber laser annealing of indium-tin-oxide nanoparticles for large area transparent conductive layers and optical film characterization , 2011 .

[11]  P. Löbmann,et al.  Modified procedure for the sol–gel processing of indium–tin oxide (ITO) films , 2008 .

[12]  P. Wellmann,et al.  Conductivity and adhesion enhancement in low-temperature processed indium tin oxide/polymer nanocomposites , 2010 .

[13]  F. E. Karasz,et al.  Indium tin oxide nanoparticles as anode for light-emitting diodes , 2006 .

[14]  A. Winnacker,et al.  Electrical, optical and morphological properties of nanoparticle indium–tin–oxide layers , 2007 .

[15]  Arno Kwade,et al.  Wet comminution in stirred media mills — research and its practical application , 1999 .

[16]  Y. Topkaya,et al.  Slag treatment at Kardemir integrated iron and steel works , 2004 .

[17]  Soon-Gil Yoon,et al.  Influence of laser treatment on the electrical properties of plasma-enhanced-atomic-layer-deposited TiO2 thin films , 2005 .

[18]  W. Peukert,et al.  Evaluation of the film formation and the charge transport mechanism of indium tin oxide nanoparticle films , 2010 .

[19]  E. Kraker,et al.  Wet chemical deposited ITO coatings on flexible substrates for organic photodiodes , 2009 .

[20]  C. Granqvist,et al.  Indium tin oxide films made from nanoparticles: models for the optical and electrical properties , 2003 .

[21]  Michael Schmidt,et al.  CO2-laser treatment of indium tin oxide nanoparticle coatings on flexible polyethyleneterephthalate substrates , 2010 .

[22]  Jin-seong Park,et al.  Thin film encapsulation for flexible AM-OLED: a review , 2011 .

[23]  G. Niklasson,et al.  Thin porous indium tin oxide nanoparticle films: effects of annealing in vacuum and air , 2005 .

[24]  Arno Kwade,et al.  Breaking characteristics of different materials and their effect on stress intensity and stress number in stirred media mills , 2002 .

[25]  R. Kruk,et al.  Formation of metallic indium-tin phase from indium-tin-oxide nanoparticles under reducing conditions and its influence on the electrical properties , 2008 .