Indium tin oxide

About: Indium tin oxide is a research topic. Over the lifetime, 17857 publications have been published within this topic receiving 402127 citations. The topic is also known as: indium tin oxide.

Metallic and Ceramic Thin Film Thermocouples for Gas Turbine Engines

Abstract: Temperatures of hot section components in today's gas turbine engines reach as high as 1,500 °C, making in situ monitoring of the severe temperature gradients within the engine rather difficult. Therefore, there is a need to develop instrumentation (i.e., thermocouples and strain gauges) for these turbine engines that can survive these harsh environments. Refractory metal and ceramic thin film thermocouples are well suited for this task since they have excellent chemical and electrical stability at high temperatures in oxidizing atmospheres, they are compatible with thermal barrier coatings commonly employed in today's engines, they have greater sensitivity than conventional wire thermocouples, and they are non-invasive to combustion aerodynamics in the engine. Thin film thermocouples based on platinum:palladium and indium oxynitride:indium tin oxynitride as well as their oxide counterparts have been developed for this purpose and have proven to be more stable than conventional type-S and type-K thin film thermocouples. The metallic and ceramic thin film thermocouples described within this paper exhibited remarkable stability and drift rates similar to bulk (wire) thermocouples.

Templated electrochemical deposition of nanostructured macroporous PbO2

Abstract: We report a simple method for the preparation of novel nanostructured macroporous α- and β-PbO2 films with arrays of spherical pores arranged in a highly ordered close-packed structure. The nanostructured macroporous α- and β-PbO2 films were prepared by electrochemical deposition through the interstitial spaces between polystyrene spheres (500 or 750 nm in diameter) assembled on gold or indium tin oxide substrates. After deposition, the template was removed by dissolving in toluene to leave PbO2 films that have the inverse structure of the original template. Scanning electron microscopy and X-ray characterisation of the films shows a well-formed regular three-dimensional, porous α- or β-PbO2 framework, with the spherical pores arranged in a highly ordered close-packed three-dimensional structure. The spherical pores have the same diameter as the latex spheres used to form the templates and are interconnected through a series of smaller pores. The oxide frameworks are highly polycrystalline, self-supporting and free from defects. The confinement of α-PbO2 and β-PbO2 in the interstitial spaces between the polystyrene spheres that make up the template does not affect the mechanism of nucleation and deposition or the crystal structure of the oxide, as confirmed by scanning electron microscopy and X-ray characterisation. The electrochemical activity of the resulting macroporous β-PbO2 is greater than that of the corresponding plain film, as determined by the charge passed to convert the β-PbO2 to PbSO4 on electrochemical cycling in H2SO4. Due to the increase in volume accompanying the electrochemical conversion of β-PbO2 to PbSO4, the macroporosity of the film is significantly degraded and the electrochemical activity decreased after a few cycles in sulfuric acid.

Chemical and thermal treatment of PEDOT:PSS thin films for use in organic light emitting diodes

Abstract: We have investigated the effects of thermal and chemical treatments on the optical and electrical properties of poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT:PSS), a doped polymer widely used as a buffer layer to increase the stability and the charge injection in organic light emitting diodes (OLEDs). Thermal treatments carried out on thin films in the temperature range of 120–250 °C did not strongly modify the structure of the polymer as proved by Raman and infrared measurements while their resistivity increased with increasing temperature. Chemical treatment of different durations by 10% hydrochloric acid showed a strong increase in the conductivity but the structure of the polymer was generally preserved. X-Ray photoelectron spectroscopic analysis of the treated films indicated a partial change of their composition, which favoured the electronic conduction upon acid treatments. When using PEDOT:PSS as a buffer layer on indium tin oxide substrates, a diffusion of indium was observed in the as-deposited polymer films. A thermal treatment most probably increased the diffusion and an acid treatment removed the diffused metal. A combination of these treatments appears to be the best way to improve the quality of the films for their use in OLEDs.

Marked improvement in electroluminescence characteristics of organic light-emitting diodes using an ultrathin hole-injection layer of molybdenum oxide

Abstract: We show that the performance of organic light-emitting diodes (OLEDs) is markedly improved by optimizing the thickness of a hole-injection layer (HIL) of molybdenum oxide (MoO3) inserted between indium tin oxide and N,N′-diphenyl-N,N′-bis(1-naphthyl)-1,1′-biphenyl-4,4′-diamine (α-NPD). From results of the electroluminescence (EL) characteristics of OLEDs with various thicknesses of a MoO3 HIL, we found that the OLED with a 0.75-nm-thick MoO3 HIL had the lowest driving voltage and the highest power conversion efficiency among the OLEDs. Moreover, the operational lifetime of the OLED was improved by about a factor of 6 by using the 0.75-nm-thick MoO3 HIL. These enhanced EL characteristics are attributable to the formation of an Ohmic contact at the interfaces composed of ITO/MoO3/α-NPD.