Performance evaluation of the indium zinc oxide (IZO) thin films for organic electroluminescent diode applications

Abstract

In this report, the transparent conducting indium zinc oxide (IZO) films (60–220 nm) have been grown on hardness poly-carbonate (HPC) substrate without a post deposition annealing treatment. The direct current (dc) magnetron sputtering system was employed for the film deposition. The IZO alloy target (99.99% and 95% in purity and density, respectively) is composed of 90 wt.% of In <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> and 10 wt.% of ZnO. The electrical, optical, and structural properties of these prepared films by different dc powers, such as 50W, 80W and 100W, without/with the ion-assisted deposition (IAD) technique. An optimum IZO deposition condition is developed for flexible organic light-emitting device (OLED) applications. The IZO films grown at low temperature (∼ 50°C) by the dc magnetron sputtering (100-W power) with the IAD technique were used to study the electroluminescence (EL) performance of OLEDs. Under a current density of 200 (mA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ), the developed OLED/IZO/HPC substrate shows an excellent efficiency (5 V turn-on voltage) and a luminance of 1800 (cd/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) in average, which is better than that measured with commercial indium-tin oxide (ITO) anodes and well above the electro-optical application standard.