ITO Substrate Research Articles

Effect of Substrate-induced Strains on Ferroelectric and Dielectric Properties of Lead Zirconate Titanate Films Prepared by the Sol-gel Technique

Background: Lead Zirconate Titanate (PZT) films were synthesized by sol gel technique. The growth of films on ITO, Si\SiO2\Ti\Au, Si\Au and Si\SiO2\Ti\Al substrates discussed. In this study, Zirconium nitrate, lead acetate, and Ti (IV) isoproxide used as raw materials. Besides, acetic acid used as a solvent and 2-methoxy ethanol used as a stabilizer for Ti structure. Along with this, PZT films have perovskite structure, thin-film perovskite structure with high dielectric properties and hysteresis loop have been investigated. Methods: The effects of the type’s substrate on dielectric properties the ferroelectric properties were investigated and compared PZT film which deposited in different substrates. The films annealed at 600°C to complete crystalline films. XRD shows tetragonal PZT films have a strong perovskite structure with [100] prefer plane orientation. SEM and cross-section technique used to study for PZT surface films. Results: The dielectric constant at room temperature was different values depending on the types of substrate. The dielectric properties of the PZT films measured at 1 kHz were 120-400 dielectric constant and dielectric loss 0.02-0.08 at room temperature and 1 kHz. Conclusion: The largest remnant polarization (Pr) and coercive field (Ec) are obtained for PZT film deposited on Si\SiO2\Ti\Au substrate, equal to 26.6 mC/cm2 and 38.3 kV/cm, as compared to 16.3 mC/cm2 and 32.2 kV/cm2 for PZT film deposited on ITO substrate.

Infrared Switching of Self-Heating VO<sub>2</sub>/ITO Films for Smart Window

The unique metal to insulator transition (MIT) of vanadium dioxide (VO2) makes it receiving extensive attention in the application of smart window. As for VO2-based smart window, the critical transition temperature (Tc) is required to be reduced to near room temperature for practical applications. In this paper, we fabricated VO2 films on ITO glass by hydrothermal method and applied voltage to ITO, therefore, the joule heat generated by ITO triggered the complete MIT of VO2 at room temperature in very short time ~3 s with applied voltage of 12 V. The VO2 film on ITO substrate shows obviously widened hysteresis behavior in the reversible transition process with a thermal hysteresis width of ~33 °C. The widened hysteresis loop makes it possible to stabilize the rutile phase (R) of VO2 at room temperature via applying a low holding voltage of 6 V. The proposed VO2/ITO film exhibits promising application in active smart window, and possesses advantages of simple structure, easy-fabricated and low-cost.

Impact of precursor concentrations and substrate type on properties of electrodeposited CdO nanorod thin films for optoelectronic applications

We present here the fabrication of CdO nanorod thin films employing electrochemical deposition technique as low temperature and economical method. Effect of cadmium ions precursor and substrate type were deeply studied to examine structural, morphology, and optical properties of deposited thin films utilizing XRD, SEM, UV–Vis, and PL spectroscopy techniques, respectively. The results designate the formation of a pure phase of face-centered cubic for CdO thin films for different ion concentrations and both substrates. Grown samples have surface morphology of nanorods that changed to nanosheets with increasing Cd+2 ions concentration on ITO substrates while for FTO substrates, it has the same shape with a small decrease in grain sizes. Band gap energy was estimated from the Tauc equation that has average values from 2.5 to 2.2 eV and from 2.5 to 2.3 eV for ITO and FTO, respectively with increasing of molarity from 0.2 to 0.8 M. The growth rate and the conductivity of substrates are the main factors for obtaining different structure, morphology, and different optical band gaps for the fabricated CdO samples as confirmed by current-time curves of electrodeposition process. Photoresponse of the fabricated CdO thin films was evaluated under dark and light conditions. Therefore, our results indicate that the electrodeposited CdO nanorods and nanosheets shapes with different bandgap energy is a promising candidate for the fabrication of optoelectronic devices.

Charge Transfer in Conjugated Polymer Mxene Interface

Optimization of charge generation and charge transport is crucial for the fabrication of highly efficient polymer solar cells. In the present work, using ultrafast pump-probe spectroscopy and atomic force microscopy, we showed the efficient charge generation and transport at polymer blend MXene interface compared to PEDOT:PSS interface. We observed long charge carrier lifetime, strong photoluminescence of donors and acceptors and higher current on PBDB:ITIC thin film prepared on ITO substrate with MXene. Our study provides the guidelines for the fabrication of inexpensive, flexible, and highly flexible polymer solar cells by interface tuning.

Preparation and optical properties of Au nanoparticle “Sandwich” structure (AuNPs/ZNNs/AuNPs) substrate based on ZnO nanosheets template

Surface enhancement Raman scatting (SERS) substrate was synthesized by two-step electrodeposition method based on ZnO nanosheets (ZNNs) template. ZNNs membrane was prepared via first-electrodeposition by using zinc nitrate hexahydrate (ZnNO3•6H2O) as the precursor. Subsequently, an Au seed layer was coated on the ZNNs membrane substrate using ion sputtering apparatus. Finally, Au nanoparticles composite membrane was obtained by the second-electrodeposition growth process of Au nanoparticles in chlorogenic acid (HAuCl4•4H2O) solution. The Au nanoparticles composite membrane could be served as an activity SERS substrate, and it showed that ZNNs are mutually hinged and grow vertically ITO substrate and Au nanoparticles grew along the (111) crystalline orientation. Results demonstrate that Au nanoparticles with an average diameter of 50 nm are uniformly deposited on the surface of ZNNs template, and the as-prepared AuNPs/ZNNs/AuNPs “sandwich” structures membrane was a high activity and sensetivity SERS substrate, it showed a rather low detection limitation of 10−12 mol/L for R6G solution.

Comparative study of nucleation and growth mechanism of cobalt electrodeposited on ITO substrate in nitrate and chloride electrolytes

Comparative study of nucleation and growth mechanism of cobalt electrodeposited on ITO substrate in nitrate and chloride electrolytes

Enhanced Electrochemical Performance of Hydrothermally Exfoliated Hexagonal Boron Nitride Nanosheets for Applications in Electrochemistry

Two-dimensional (2D) morphology of hexagonal boron nitride (h-BN), owing to its peculiar characteristics of non-toxicity and uniquely featured oxidation resistance has attracted extensive attention in electrochemical applications. Here, we report a facile top-down approach for the successful synthesis of hexagonal boron nitride nanosheets (h-BNNS) through a low-temperature hydrothermal method. The structural and spectroscopic characterizations have been performed using XRD, FT-IR, Raman and UV-Visible Spectroscopy that reveals incorporation of maximum induced strain, multifunctional groups and formation of few layers h-BNNS. The nanosheets morphology is confirmed by series of characterizations (SEM, TEM, and AFM) revealing the large lateral size and relatively low surface roughness of h-BNNS. The electrodes for electrochemical characterizations are prepared using the electrophoretic deposition (EPD) technique onto ITO substrates with the help of magnesium nitrate [Mg(NO3)2·6H2O] as a mediator. Electrochemical Studies has been performed in phosphate buffer saline (PBS) with Ferro-ferricyanide [Fe(CN)6]3−/4− as a redox couple. Cyclic voltammogram of h-BNNS (Ipa = 1.29 mA and Ipc = −1.23 mA) indicates 69.96% enhancement in redox peaks current and 71.04% rise in electro-active surface area with respect to Bulk h-BN. The electrochemical studies uncover the potential of h-BNNS in the development of electroanalytical devices in applications such as sensing, anticorrosion, energy conversion and energy storage applications owing to their enhanced redox peaks, large electroactive surface area, and reduced charge transfer resistance as well as the admittance of Warburg element.

12‐1: Controlling the Pixel Colors of Quantum Dot Thin Films by Patterning the Substrates

The common methods to achieve high resolution of patterned QD thin films are photolithography of QD thin films and ink‐jet printing of QD thin films. To avoid damages on QDs caused by photolithography and further increase the resolution of the patterned QD, a new method, i.e. selective extraction of lightemission by patterning the bottom electrode instead, was developed in this work. The theory of this method is based on optical interference. Patterning the ITO substrates offers more flexibility and higher resolution, since ITO is more robust and resistive to damages related to photolithography.

Fabrication of dye-sensitized solar cells with ZnO nanorods as photoanode and natural dye extract as sensitizer

Highly oriented zinc oxide nanorods (ZnO NRs) have been grown on ITO substrates at various growth times using hydrothermal method. The necessary ZnO seed layers on ITO have been deposited using spray pyrolysis. Both the methods have been successfully applied to prepare efficient ZnO NRs-based photoanodes for DSSCs. FESEM images revealed the vertical growth of ZnO NRs from the substrates with a length and diameter ranges of 1.2–1.5 μm and 80–120 nm, respectively. The XRD and HRTEM results confirmed the hexagonal structure with preferential orientation (c-axis) of ZnO NRs. The high optical transmittance (90%) was observed in the visible region for the ZnO NRs grown for 9 h. A decrease in optical bandgap was noticed with the increase of growth times. The natural dye extract absorbed in to the ZnO NRs exhibited a broad absorption peak in UV–Vis spectra analysis. The power conversion efficiency of DSSCs prepared with ZnO NRs (9 h) as photoanode showed better performance compared to other growth times.

Effect of laser power density on the electrochromic properties of WO3 films obtained by pulsed laser deposition

Pulsed laser deposition (PLD) was used to prepare tungsten trioxide (WO3) films on ITO substrates with a varying laser power density of 4.0–5.5 W/cm2. XPS indicated that when the laser power density decreased, the peak positions of the W 4f and O 1s orbits shifted slightly to low energy due to the difference in oxygen vacancies. As the laser power density decreased, W6+ gradually replaced the lattice position of O2−, increasing oxygen vacancies in the lattice. The transmittance modulated values (ΔT) were over 44% at 830 nm, indicating strong absorption by the WO3 thin films in the near-infrared ray. The switching time of the WO3 thin films between bleached states and coloured states decreased as the laser power density increased due to the amorphous structure, morphology, and lower oxygen deficiency at a high power density. The high ΔT and very fast switching time of tb (1.09 s) and tc (6.01 s) demonstrated the excellent electrochromic (EC) properties of the WO3 films prepared by PLD.

Structural and Electrochemical Analysis of CIGS: Cr Crystalline Nanopowders and Thin Films Deposited onto ITO Substrates.

A new approach for the synthesis of nanopowders and thin films of CuInGaSe2 (CIGS) chalcopyrite material doped with different amounts of Cr is presented. The chalcopyrite material CuInxGa1 − xSe2 was doped using Cr to form a new doped chalcopyrite with the structure CuInxCryGa1 − x − ySe2, where x = 0.4 and y = 0.0, 0.1, 0.2, or 0.3. The electrical properties of CuInx CryGa1 − x − ySe2 are highly dependent on the Cr content and results show these materials as promising dopants for the fabrication thin film solar cells. The CIGS nano-precursor powder was initially synthesized via an autoclave method, and then converted into thin films over transparent substrates. Both crystalline precursor powders and thin films deposited onto ITO substrates following a spin-coating process were subsequently characterized using XRD, SEM, HR-TEM, UV–visible and electrochemical impedance spectroscopy (EIS). EIS measurement was performed to evaluate the dc-conductivity of these novel materials as conductive films to be applied in solar cells.

Insight into Co concentrations effect on the structural, optical, and photoelectrochemical properties of ZnO rod arrays for optoelectronic applications

Using a cost-effective and time-efficient chemical bath deposition (CBD) approach, zinc oxide (ZnO) nanorod doped with various cobalt concentrations ranged from 2% to 8% have been synthesized on ITO substrates. Different methods: including X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–Vis spectroscopy, photoluminescence spectrometry (PL), current-voltage (I–V), and photocurrent were employed to investigate the structural, morphological, optical, and photoelectrochemical. XRD results confirmed that rod arrays formed in hexagonal structure with favorite orientated in (002) plane. SEM images revealed at all doping levels that there were hexagonally shaped nanorods of ZnO, which agreed with XRD measurements. UV–visible measurements indicate an absorption band edge at 381 nm which, is mainly recognized as a characteristic direct bandgap for ZnO arrays. In doped samples; other absorption band edges observed at 562, 605, and 654 nm correspond to the d-d transformation of Co2+ ions. The calculated value of band gap energy (Eg) reduced with the increasing of the Co dopant ions. The PL spectra exposed near band edge emission and defect-related visible emission band. Photocurrent analysis showed that the fabricated arrays have an n-type conductivity. Moreover, the photocurrent enhancement with increasing doping concentration where 6% Co ions have the highest value. The results show that Co doped ZnO nanorods are talented candidates for solar cells and biosensors applications.

Sonochemical exfoliation, characterization and photoresponse of MoS0.5Se1.5 nanosheets

Recently, transition metal dichalcogenide have gained significant attention from researchers due to their extraordinary optoelectronic properties. Here we evaluate the photodetection properties of highly crystalline nanosheets of MoS0.5Se1.5 synthesized by high yield sonochemical exfoliation technique. Constituent elements have been verified by EDAX. The results of powder XRD shows highly crystalline nature of nanosheets and XRD pattern is well indexed to 2H-hexagonal lattice structure with P63/mmc space group. Transmission Electron Microscopy is conducted in order to find the structural details for the nanosheets of MoS0.5Se1.5. Picked Field Electron Diffraction pattern indicated the highly crystalline existence of the nanosheets. Drop casting method was utilized to deposit thin film of MoS0.5Se1.5 nanosheets on ITO substrate. Efforts have been made to study the photoresponse of MoS0.5Se1.5 thin film using 670 nm light having power intensity 3mv/cm2. The intensify photoresponsivity of 1.62 mA/W and specific detectivity of 1.3*108 Jones is observed. The present findings suggest effective way to tune bandgap for producing high-performance optoelectronic device.

Mechanism of the Alcohol-Soluble Ionic Organic Interlayer in Organic Solar Cells.

In this article combining density functional theory (DFT) calculations and corresponding experimental measurements, the adsorption behaviors and working mechanism of the alcohol-soluble ionic organic interlayer on different electrode substrates were studied. The results suggest that, when the ionic organic bipyridine salt interlayer (FPyBr) is adsorbed on the Ag surface, Br- will break away from molecule chains and form new chemical bonds with the Ag substrate, as confirmed by both the X-ray photoelectron spectroscopy (XPS) study and DFT study for the first time. Charges are further found to transfer to the Ag substrate from the new interlayer molecular structure without Br-, resulting in adsorption dipoles directed from Ag to the interlayer. Moreover, the direction of the intrinsic dipole of the molecule itself on the Ag substrate is also verified, which is the same as that of the adsorption dipole. Subsequently, the superposition of the two dipoles results in a large reduction of the Ag substrate work function. In addition, the dipole formation mechanism of the interlayer on the ITO surface was also studied. The change in the work function of the ITO substrate by this interlayer is found to be smaller than that of Ag as confirmed by both a DFT study and scanning Kelvin probe microscopy (SKPM) results, which is mainly due to the reversed direction of the molecular intrinsic dipole with respect to the interfacial dipole. The worst device performance of organic solar cells based on the ITO-FPyBr substrate is considered to be one of the consequences of the feature. The findings here are of great importance for the study of the mechanism of the ionic organic interlayer in organic electronic devices, providing insightful understandings on how to further improve the material and device performance.

Preparation Of (Cu-TiO2) Thin Films, And Used as An Antibacterial

Thin films of TiO2 and TiO2: Cu have been prepared on ITO substrates using RF magnetron sputtering technique, It is worthy to say that the thickness of the coated film was in the order of (220) nm. The films annealing in air at temperature 500 °C with 2 h. Optical of structural properties were identified with various preparation conditions like Cu-doping concentration (0%, 2% and 4%). These prepared films are polycrystalline with a anatase crystal structure. The crystallinity and the size of particle of the samples of prepared were studied by (XRD), the results specified the size of particle of the samples of prepared dropped with the high of Cu doping concentrations some of the properties of structure are varied by the addition Cu levels as dopants. The films are oriented of preferentially forever the (101) direction. We have got some morphology of surface by (SEM), the results show decreasing of particle size with increasing doping concentration. The results show that the doping caused to decreased the transmittance and energy gap from (3.6 to 3.4) eV. Activity antibacterial efficiency was estimated by the un activation of E.coli. It was spotted that rising Cu levels gives better activity of antibacterial.

Enhanced performance of UV photodetector of MoS2 quantum dots-decorated ZnO nanorods

Two-dimensional transition metal dichalcogenides such as molybdenum disulfide (MoS2) have attracted great attention due to their unique optical, electrical and chemical properties. MoS2 quantum dots (QDs) exhibit strong quantum confinement, high surface area and notable active edge sites compared to their bulk. In this work, MoS2 QDs were attached on the surface of ZnO nanorods (NRs) grown on interdigitated ITO substrates and then used as photodetector. MoS2 QDs were synthesized by a new ultrafast way pulsed laser ablation (PLA) in liquid method and then spincoated on the surface of ZnO NRs. The pristine ZnO and ZnO/MoS2 QDs photodetector were investigated under UV and visible light (325 nm, 505 nm and 635 nm) with the bias voltage -5 V to 5 V. The results show that the decoration of ZnO NRs by MoS2 QDs could enhance the sensitivity, responsivity and detectivity under UV irradiation. This may due to the decrease of dark current as the result of passivation of surface defects of ZnO NRs by MoS2 QDs.

Electrochemical behavior of CuO/rGO nanopellets for flexible supercapacitor, non-enzymatic glucose, and H2O2 sensing application

In the present article, graphene oxide (GO) sheets and monoclinic copper oxide (CuO) nanocrystals are connected with each other and result in the formation of CuO/rGO nanopellets, and these nanopellets synthesized using coprecipitation method. The nanopellet structured CuO/rGO composite on carbon cloth, which act as current collector exhibits specific capacitance of 188 F g−1 at a current density of 0.2 A g−1 and up to 96.3% capacity retention after 2000 charge-discharge cycles. It shows a maximum energy density of 7.32 Wh kg−1 and power density of 53 W kg−1. The glucose sensing characteristics of CuO/rGO nanopellet is investigated on carbon cloth and ITO substrate. It shows glucose sensitivity of 0.805 mA mM−1 cm−2 and 0.2982 mA mM−1 cm−2 for a bundle like structured CuO/rGO composite on carbon cloth and ITO substrate, respectively. Further H2O2 sensing is studied on ITO substrate, which manifests H2O2 sensitivity of 84.39 μA mM−1 cm−2. The results indicate that nanopellet structured CuO/rGO composite could be a promising electrode material for supercapacitor, glucose, and H2O2 sensor.

Investigation of the inhibited biotoxicity of heavy metals towards 5- formylcytosine in rice by hydrochar based on photoelectrochemical biosensor

A photoelectrochemical (PEC) biosensor was constructed for 5-formylcytosine (5fC) nucleotide detection based on Ag2S@WS2 photoactive material and FeVO4 catalytic signal quenching. After Ag2S@WS2 was modified onto the ITO substrate surface, 5fC recognition reagent of Au@4-amino3hydrazino5mercapto-1,2,4-triazol (Au@AHMT) was further modified through electrostatic adsorption. Afterwards, based on the specific chemical reaction between –NH2 and –CHO, 5fC can be selectively recognized and captured. Subsequently, the nanoenzyme of FeVO4 was recognized based on the specific reaction between the phosphate group of 5fC nucleotide and Fe3+. Under the catalysis of FeVO4, the 4-chloro-1-naphthol in the detection solution can be oxidized to generate a precipitate, which will be retained on the electrode surface to inhibit the PEC signal. The developed method presented a widely dynamic range from 0.1 to 400 nM. The detection limit was 0.062 nM (3σ). This method also showed good detection selectivity, reproducibility and stability. The applicability was verified by investigating 5fC content change in genomic DNA of rice tissues after incubated with heavy metals. Moreover, the inhibited influence of hydrochar towards heavy metals was also assessed.

Formation of RuO2 thin film using dopamine as a reducing, chelating, and adhesive agent simultaneously

We demonstrate a facile and seedless wet chemical process to deposit RuO2 thin film on a glass slide. The process entails the use of dopamine and its oxidized form, polydopamine (PDA), as the reducing and chelating agent, as well as the adhesive agent bonding the RuO2 and glass slide. The formula starts with the oxidation of K2RuCl5 to prepare RuO4 solution, followed by its reduction by dopamine to form chelated RuO2 colloids for the deposition of amorphous RuO2 thin film containing 26.5 at% hydrous RuO2 and 73.5 at% RuO2. After a mild Ar annealing, the RuO2 thin film exhibits a rutile phase with (110) preferred orientation. Elemental analysis indicates incomplete pyrolysis of PDA. Results from X-ray absorption spectroscopy confirm the presence of RuO4 and its transformation to RuO2. Electrochemical analysis of the adsorbed dopamine molecules on an ITO substrate validates the oxidative behavior of dopamine. The bonding strength of RuO2 thin film is determined by a tape-peeling test in which both the as-deposited and annealed RuO2 thin films show robust adhesion to the glass substrate.

Investigation of the mechanism of a facile method for ammonia treatment to effectively tune the morphology and conductivity of PEDOT:PSS films

Although there are some advantages of PEDOT:PSS films, including high conductivity, high transparency to visible light, excellent water solubility, and being environmentally-friendly, PEDOT:PSS solutions are acidic owing to the PSS polymer with a –SO3H group donating the hydrogen ions. This results in the etching of the ITO surface as the PEDOT:PSS films are deposited on the ITO substrates using a spin coating process, which is attributed to the migration of indium and tin into the PEDOT:PSS film. In this paper, a PEDOT:PSS solution was treated with ammonia with different volume ratios prior to deposition. It is found that ammonia treatments can totally neutralize the hydrogen ions and reduce the AIn3+/AIn3+(pristine) atomic area ratio of PEDOT:PSS surface calculated from the XPS data due to the inhibition of the degradation at the PEDOT:PSS/ITO layer interface. Furthermore, the ASO3H/ASO3− on the PEDOT:PSS surface obviously changes with ammonia-treated solution at pH < 7, and APEDOT/APSS is greatly influenced by an ammonia-treated solution at pH > 7, which affects the surface energy of PEDOT:PSS film, helps improve the film roughness, and enhances the electrical conductivity of the films.