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

Emerson Roberto Santos,Roberto Koji Onmori,Marina Sparvoli Medeiros,Thiago De Carvalho Fullenbach,Wang Shu Hui,Luis Da Silva Zambom

doi:10.30886/rbav.v40.1205

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.

Highlights

Organic light-emitting diode (OLED) can be defined as organic semiconductor electroluminescent device mounted by multilayers located between two inorganic anode and cathode electrodes[1,2]
This thickness result to indium tin oxide (ITO) from Diamond Coatings was similar as the one presented by fluorine tin oxide (FTO) thin film produced at laboratory, but generally the FTOs are thicker when compared with similar conductivity, as found in the ITO thin films[48]
Commercial and produced at laboratory Transparent conductive oxides (TCOs) known as ITO and FTO were analyzed by different techniques and compared as electrode anode in organic light-emitting diode (OLED) devices using the same structure

Summary

Introduction

Organic light-emitting diode (OLED) can be defined as organic semiconductor electroluminescent device mounted by multilayers located between two inorganic anode and cathode electrodes[1,2]. A vast variation of different materials has provided different color emission used in displays of consumer products, such as: smartwatches, smartphones and TVs4,5 These devices present some important characteristics: image with good sharpness and contrast, wide gain on vision (≈180°), fidelity of color reproduction, no emission of neither ultraviolet nor infrared rays and fast time of response[6,7]. These advantages are only found in the OLED devices compared with liquid crystal displays (LCDs), for example

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