Different electrode anodes used in OLED devices Diferentes eletrodos anodos usados em dispositivos OLEDs

Abstract

Transparent conductive oxides (TCOs) known as indium tin oxide (ITO) and fluorine tin oxide (FTO) deposited on glass were compared by different techniques and also as anodes in organic light-emitting diode (OLED) devices with same structure. ITO produced at laboratory was compared with the commercial one manufactured by different companies: Diamond Coatings, Displaytech and Sigma-Aldrich, and FTO produced at laboratory was compared with the commercial one manufactured by Flexitec Company. FTO thin films produced at laboratory presented the lowest performance measured by Hall effect technique and also by I-V curve of OLED device with low electrical current and high threshold voltage. ITO thin films produced at laboratory presented elevated sheet resistance in comparison with commercial ITOs (approximately one order of magnitude greater), that can be related by a high number of defects as discontinuity of the chemical lattice or low crystalline structure. In the assembly of OLED devices with ITO and FTO produced at laboratory, neither presented luminances. ITO manufactured by Sigma-Aldrich company presented better electrical and optical characteristics, as low electrical resistivity, good wettability, favorable transmittance, perfect physicalchemical stability and lowest threshold voltage (from 3 to 4.5 V) for OLED devices.