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Low sheet resistivity, high transparency SnOx-based transparent conductive oxides for their applications in OLEDs

Research output: Contribution to conference - Without ISBN/ISSN Posterpeer-review

Published
Publication date2014
<mark>Original language</mark>English
EventEMRS 2014, Spring Meeting - France, Lille, France
Duration: 26/05/201430/05/2014

Conference

ConferenceEMRS 2014, Spring Meeting
Country/TerritoryFrance
CityLille
Period26/05/1430/05/14

Abstract

Indium-Tin-Oxide (ITO) is currently used in OLED panels for the transparent cathode and constitutes the dominant material of choice. However, indium is becoming increasingly scarce and hence an expensive resource. Also ITO itself exhibits serious technical drawbacks related to the costly deposition techniques. ITO alternatives have been investigated aiming to produce indium-reduced or indium-free oxides, conducting polymers, carbon nanotubes, graphene, nanowires and nanoparticles however they all suffer from either low optical transparency, low sheet resistivity, lower work functions than ITO, i.e. poor energetic alignment with hole transporting layer HOMO. In this work, we report the application of ambient spray pyrolysis for the deposition of highly transparent, high work function Antimony-doped Tin Oxide (ATO) thin film as OLED anodes. ATO films were studied by means of X-rays Diffraction, AFM, UV-visible absorption spectroscopy, 4-point probe, Hall Effect, Kelvin Probe and implemented in RGB OLED structures. For optimum antimony doping, the as-deposited ATO films exhibit excellent characteristics i.e. high work function (5.05 eV) wide direct band gap (4.65 eV), high transparency (90 %) in the visible spectrum, low sheet resistivity (25 Ohm/sq) and carrier mobility of 32 cm2 V-1 s-1. The antimony-doped tin oxide R,G,B, OLEDs show similar I-V and L-V characteristics to those of ITO and high external quantum efficiencies of about 12%, 0.3 % and 13% respectively.