Ag Indium Tin Oxide Research Articles

Performance Analysis of a Kretschmann-Based Ag-ITO-Au Surface Plasmon Resonance Sensor through Numerical Simulations

Variations of a Kretschmann-structure-based Ag-indium tin oxide- (ITO-) Au surface plasmon resonance (SPR) sensor were explored to improve its sensitivity. The sensor structure was optimised, and its characteristics were studied through numerical simulations. The chip structure that comprised 20 nm Ag/30 nm ITO/10 nm Au yielded the best sensing performance, wherein the angular sensitivity could reach 197.6° RIU−1 and the figure of merit was 43.4 RIU−1. These performance parameters are nearly three times higher than those of Ag/Au bimetallic resonance sensors. Furthermore, an adhesive Cr layer and two-dimensional graphene were incorporated into this sensor structure to explore their impact on the performance. The results demonstrated that the Cr layer significantly weakened the sensor performance, whereas graphene did not produce the expected enhancement effect on this structure. If simply adding a layer to a Au/Ag sensor can produce a three-fold improvement in its performance, then its economic and scientific benefits are potentially significant and widespread.

Highly Sensitive SPR Sensor Based on Ag-ITO-BlueP/TMDCs-Graphene Heterostructure

The novel surface plasmon resonance (SPR) sensor based on hybrid structure of Ag-indium tin oxide (ITO)-blue phosphorene (BlueP)/transition metal dichalcogenides (TMDCs)-graphene is presented. The BlueP/TMDCs heterostructure works as an interacting layer with the analyte for the enhancement of the of the sensor’s sensitivity. For angular sensitivity, when the BlueP/WS2 and graphene are both monolayer, the highest angular sensitivity with 348.8°/RIU is obtained. The maximum angular sensitivity of our proposed SPR sensor is about 2.83 times of the conventional sensor. For phase sensitivity, when the BlueP/WSe2 is monolayer and graphene is bilayer, the highest phase sensitivity with 3.603 × 106 deg/RIU is obtained. The highest phase sensitivity of our proposed SPR sensor is about 2.78 times of the Ag-ITO-graphene structure and 4.16 times of the Ag-ITO structure. The SPR sensor has the advantages of high sensitivity, repeatability, and reusability, so it has a good prospect application for food safety detection, biological engineering, medical diagnosis, and biochemical detection.

Sensitivity Enhancement of Ag-ITO-TMDCs-Graphene Nanostructure Based on Surface Plasmon Resonance Biosensors

The novel configuration of surface plasmon resonance (SPR) based on Ag-indium tin oxide (ITO)-transition metal dichalcogenides (TMDCs)-graphene hybrid structures is proposed for highly sensitivity biosensor. When the WS2 and graphene are 3 layers and monolayer, respectively, the highest angular sensitivity up to 213.2°/RIU is obtained. Moreover, sensing media with different refractive indices can be detected by SPR biosensor. The phase sensitivity of 3.6 × 106 deg/RIU is obtained when the MoS2 and graphene are 3 layers and 4 layers, respectively. The highest phase sensitivity of the proposed SPR biosensor is about 2.79 times the Ag-ITO-MoS2-graphene structure and 4.16 times the Ag-ITO hybrid structure. The SPR biosensor has the advantages of high phase sensitivity, reusability, and reproducibility which make the sensor have the potential application prospects in medical diagnosis, environmental, and biochemical detection.

Comprehensive Study of Phase-Sensitive SPR Sensor Based on Metal–ITO Hybrid Multilayer

Surface plasmon resonance (SPR) biosensor is widely used for its high precision and real-time analysis. In this paper, SPR biosensor based on the hybrid structure of metal–indium tin oxide (ITO)–WS2 are proposed and investigated. By optimizing the thickness of metals (Au, Cu, Ag), ITO and WS2, the reflectivity of 2.932 × 10−7 a.u and highest phase sensitivity of 1.711 × 106 deg/RIU are obtained by using Ag–ITO–WS2-dielectric structure. Compared with the traditional metal-based SPR sensor, the performance of the proposed one is improved up to ~ 25.8 times. The results show that ITO and WS2 have an important effect on enhancing SPR sensing performance.

Analysis of Localized Surface Plasmon Resonance in Ag/ITO/CdS/SiO2 Multilayered Nanostructured Composite

Multilayered nanoshells have attracted much attention due to their unique optical, electronic and magnetic properties. In this work, numerical calculation using discrete dipole approximation (DDA) is conducted to investigate the quad-layered metal nanoshell consisting of a particle with a dielectric silica (SiO2) core, inner cadium sulfide (CdS) shell, middle indium tin oxide (ITO) shell and outer metal silver (Ag) shell. The phenomenon is interpreted by plasmon hybridization theory and the Ag–ITO–CdS–SiO2 multilayered nanoshells are studied by extinction spectra of localized surface plasmon resonance. The variation in the spectrum peak with nanoparticle thickness and refractive index of the surrounding medium is derived. The electric field enhancement contour around the nanoparticles under illumination is analyzed at the plasmon resonance wavelength. The [Formula: see text], [Formula: see text], and [Formula: see text] modes red-shift with the refractive index of the surrounding medium and increase in the layer thickness causes either blue-shift or red-shift as shown by the extinction spectra. The mechanism of the red-shift or blue-shift is discussed. The [Formula: see text] mode blue-shifts and furthermore, the [Formula: see text] and [Formula: see text] modes of the Ag coated multilayered nanostructure are noticeable by comparing the extinction efficiency spectra of the Au–ITO–CdS–SiO2 and Ag–ITO–CdS–SiO2 multilayered nanoshells.

Tribo-corrosion of Ag and Ag-alloy ITO multilayers used in solar energy applications

The efficiency and long term reliability of multilayered films of Ag/Ag-alloy based indium tin oxide (ITO) used in solar energy applications depend on the surface integrity of the film. Surface integrity can be breached due to exposure to a harsh outdoor environment and mishandling. It is therefore important to study the tribo-corrosion properties of such film systems. Reciprocating polytetrafluoroethylene (PTFE) ball-on-film tests are conducted in a NaCl solution under moderate loading conditions and increasing number of cycles. Ag, Ag–Pd and Ag–Au alloy based ITO multilayers, deposited on a polymer substrate, are used and the tribo-corrosion resistance is investigated. Electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy are used, after testing, in order to characterize and determine the corrosion and wear mechanisms. The effect of the reciprocating cycles on the multilayer failure initiation and propagation is studied. The resulting tribo-corrosion mechanisms are observed using scanning electron and optical microscopy. Understanding the tribo-corrosion properties of such model multilayers can lead to increasing the efficiency and long term reliability of various solar energy and energy-efficient systems.

Surface potential behaviors of UV treated of Ag anode for high-performance T-OLED by nanotribology

A high reflective bottom anode is essential for high-performance top-emitting organic light emitting devices (OLEDs). Ag has high reflectivity for visible light but its electronic properties are not ideal for anodes of OLEDs. Thus, we investigated the UV treatment effect of Ag film with a thin silver oxide layer at the surface for application of top-emitting OLEDs. In this study, we measured the change of potential difference between Ag film and ITO (indium tin oxide) films, according to UV treatment time and the mechanical properties by KPFM (Kelvin Probe Force Microscope) method and nano-indenter system, respectively. The KPFM and nano-indenter results show that the differences of surface potential and surface volume change according to UV treatment time.

Effect of Ag thickness on electrical transport and optical properties of indium tin oxide–Ag–indium tin oxide multilayers

We report the dependence of electronic and optical properties on the Ag thickness in transparent conductive indium tin oxide (ITO)-Ag-ITO (IMI) multilayer films deposited on polyethylene naphthalate flexible substrate by sputtering at room temperature. The electrical properties (such as carrier concentration, mobility, and resistivity) changed significantly with incorporation of Ag between the ITO layers. Comparison of sheet resistance of the IMI multilayers and the calculated sheet resistance of the Ag midlayer indicates that most of the conduction is through the Ag film. The critical thickness of Ag to form a continuous conducting layer is found to be 8 nm using electrical and optical analysis. A conduction mechanism is proposed to elucidate the mobility variation with increased Ag thickness. Carrier transport is limited by either interface scattering or grain-boundary scattering depending on the thickness of the Ag midlayer. Interface scattering is dominant for thinner (5.5–7 nm) Ag and grain-boundary scattering is dominant for thicker (8–10.5 nm) Ag midlayers. In addition, the effect of varying Ag midlayer thickness on transmittance behavior is also discussed. A figure of merit is used to compare performance of the IMI multilayer systems as a function of Ag thickness.

Highly efficient transparent organic light-emitting diodes by ion beam assisted deposition-prepared indium tin oxide cathode

The authors have investigated the effects of indium tin oxide (ITO) deposited by ion beam assisted e-beam evaporation on the performance of polymer light-emitting diodes. ITO was evaporated as a cathode onto a thin Mg:Ag layer by an e-beam process, and its performance as a transparent cathode was subsequently compared to that of Mg:Ag and sputtering-prepared ITO. Polymer devices’ luminance and efficiency were improved by more than ten times by ion beam assisted deposition (IBAD)-prepared ITO deposition, with little observable damage to the organic layer. Implementation of the IBAD process resulted in the reduction of the interfacial energy barrier which induced band bending. Furthermore, outcoupling with ITO resulted in enhanced luminance.

Improvement of the luminous intensity of light-emitting diodes by using highly transparent Ag-indium tin oxide p-type ohmic contacts

We have investigated Ag-indium tin oxide (ITO) scheme for obtaining high-quality p-type ohmic contacts for GaN-based light-emitting diodes (LEDs). The Ag(1 nm)-ITO(200 nm) contacts exhibit greatly improved electrical characteristics when annealed at temperatures in the range 400/spl deg/C-600/spl deg/C for 1 min in air, yielding specific contact resistances of /spl sim/10/sup -4/ /spl Omega//spl middot/cm/sup 2/. In addition, the contacts give transmittance of about 96% at 460 nm, which is far better than that of the conventionally used oxidized Ni-Au contacts. It is shown that the luminous intensity of blue LEDs fabricated with the Ag-ITO contacts is about three times higher than that of LEDs with oxidized Ni-Au contacts. This result strongly indicates that the Ag-ITO scheme can serve as a highly promising p-type ohmic contact for the realization of high brightness near ultraviolet LEDs.

Highly flexible transparent electrodes for organic light-emitting diode-based displays

Multilayer indium-tin-oxide (ITO)–Ag–ITO stacks were evaluated as transparent conductors for flexible organic light-emitting diode (OLED) displays. The ITO–metal–ITO (IMI) samples exhibited significantly reduced sheet resistance over ITO and greater than 80% optical transmission. The IMI films deposited on plastic substrates showed dramatically improved mechanical properties when subjected to bending both as a function of radius of curvature as well as number of cycles to a fixed radius. OLEDs were fabricated on both ITO and IMI anodes, and the devices with IMI anodes showed improved performance at current densities greater than 1mA∕cm2 due to the improved conductivity of the anode.

Effects of thermal treatment on the electrical and optical properties of silver-based indium tin oxide/metal/indium tin oxide structures

In this article, we report the results of the study of thermal treatment effects on the electrical and optical properties of silver-based indium tin oxide/metal/indium tin oxide (IMI) multilayer films. Heat treatment conditions such as temperature and gaseous atmosphere was varied to obtain better electrical and optical properties. We obtained improved electrical properties and observed considerable shift in the transmittance curves after heat treatment. Several analytical tools such as X-ray diffraction, spectroscopic ellipsometer and spectrophotometer were used to explore the causes of the changes in electrical and optical properties. The sheet resistance of the structure was severely influenced by deposition conditions of the indium tin oxide (ITO) layer at the top. Moreover, the shift of optical transmittance could be explained on the basis of the change in refractive indices of ITO layers during heat treatment. The properties of Ag-alloy-based IMI films were compared with those of pure Ag-based ones. Some defects originating from Ag layer corrosion were observed on the surface of ITO-pure Ag–ITO structures, however, their number decreased significantly in the cases of Ag-alloys containing Pd, Au and Cu, though the resistivity values of Ag-alloys were slightly higher than those of silver. Atomic force microscopy measurement results revealed that the surface of the IMI multilayer was so smooth that it meets the required qualifications as the bottom electrode of organic light emitting diodes.