ITO-coated Polyethylene Terephthalate Research Articles

Optically transparent dual-band antenna for UHF and S-band applications

This paper presents a novel optically transparent antenna that utilizes Indium Tin Oxide-coated Polyethylene Terephthalate (ITO-PET) and Soda-lime-glass (SLG) substrate. It explores ITO-PET and SLG for transparent antenna fabrication, thoroughly evaluating the antenna’s performance in relation to ITO-PET’s conductivity. Operating in dual bands (1.6–2 GHz UHF and 3.25–4.95 GHz S-band), the antenna’s inventive design features a slotted circular structure with a modified ground plane, crucial for achieving dual-band functionality. Despite ITO-PET’s relatively low conductivity, the antenna outperforms expectations, exhibiting a wider bandwidth in the higher band and positive gain in both bands, conforming the potential of ITO-PET. The successful realization of this innovative concept is validated through the fabrication and measurement of the antenna prototype, signaling a new frontier in transparent antenna technology.

Influence of buffer layer on copper doped tin sulfide solar cell: A Numerical approach

The proposed paper has examined the copper tin sulfide (CTS) semiconductor which is a ternary compound with extremely high absorption coefficient (105 cm−1) and ideal bandgap ranging from 0.9 to 1.6 eV. Non-toxic and widely available elements present on the earth constitute the elements of CTS. In this work, we have numerically simulated the structure: ITO coated polyethylene terephthalate (PET)/ZnO/(CdS, ZnS, CdZnS, TiO2)/CTS/Al using wx-AMPS software.In the structure different layers are: ITO coated PET which is a flexible substrate and acting as a front layer. It has been optimized by optimizing its layer thickness as 140 nm; ZnO as intrinsic layer; CdS/ZnS/CdZnS/TiO2 as buffer layers; CTS as absorber layer and Al as back contact. Different buffer layer variation was studied by varying its thickness and donor concentration. The QE curve shown in the result shows that at lower wavelength also, the QE value for CdZnS and TiO2 is high. Therefore, for furthermore investigation, these two buffer layers were considered. After optimizing the buffer layer, absorber layer optimization was carried out by varying its thickness, acceptor concentration and defect density values. By considering CdZnS as buffer layer, the optimized result which we got as, VOC = 0.819 V, JSC = 25.77 mA/cm2, FF = 85.59 %, η = 18.08 % and by considering TiO2 as buffer layer, the optimized result which we got as, VOC = 0.818 V, JSC = 25.55 mA/cm2, FF = 84.41 %, η = 17.66 %.

Increase the current density and reduce the defects of ZnO by modification of the band gap edges with Cu ions implantation for efficient, flexible dye-sensitized solar cells (FDSSCs)

Flexible dye-sensitized solar cells (FDSSCs) have good potential in future photovoltaic technology. The spin coating method deposited the ZnO films on indium-tin-oxide-coated polyethylene terephthalate (ITO-PET) flexible plastic substrates. These films are implanted with Cu-ions with 1 × 1013 ions/cm2, 1 × 1014 ions/cm2, and 1 × 1015 ions/cm2. All the films have a hexagonal structure. The film irradiated with 1 × 1014 ions/cm2 showed high crystallinity and crystallite size. Important optical properties like bandgap energy (Eg), band edges, refractive index, extinction coefficient, and dielectric constants are measured by UV–Vis spectroscopy. Bandgap energy decreases, and the refractive index increases at the fluence of Cu ions. The maximum decrease in Eg is observed at the 1 × 1014 ions/cm2 dose. Photoluminescence spectra suggest that defects-related emission peaks are decreased at 1 × 1014 ions/cm2 Cu ions fluency. J-V measurements have significantly improved photovoltaic performance compared to pristine ZnO-based solar cells. The highest efficiency (2.30%) is observed at a 1 × 1014 ions/cm2 dose. The efficiency increase is related to improving the charge transfer ratio and shifting the fermi level toward the conduction band.

P(VDF-TrFE)/BaTiO3 nanocomposite Langmuir-Schaefer thin film for piezoelectric nanogenerator

In this study, a piezoelectric nanogenerator (PENG) was fabricated based on nanocomposite thin films comprising piezoelectric poly(vinylidenefluoride-co-trifluoroethylene) (P(VDF-TrFE)) as a matrix and BaTiO3 (BTO) nanoparticles (NPs) as a nanofiller. The Langmuir-Schaefer (LS) technique was employed to prepare the films. A mixed solution of the polymer and ceramic NPs was spread on the surface of water subphase at a predetermined surface pressure, and thin films were then prepared by transferring the spread monolayer onto indium tin oxide-coated polyethylene terephthalate (ITO-PET) substrate multiple times at a constant surface pressure. Microstructure, crystallinity, β-phase content, dielectric constant, and piezoelectric coefficient (d33) of the thin films were measured with SEM, XRD, FT-IR, LCR meter, and Quasi-static meter, respectively. Six different PENG devices with different BTO contents were fabricated by arranging the thin film-coated substrates in sandwich structure, and they were subject to measurements of piezoelectric characteristics such as open-circuit output voltage (VOC) and short-circuit current (ISC). As results, it was found that the PENG with 4 wt% BTO with ten layers of monolayer deposited at the surface pressure of 15 mN/m yielded the highest VOC of 71.4 V, which was higher than pristine polymer LS film’s 66.2 V at the same conditions, and power density of 35.7 μW/cm2 at 2.5 Hz bending-releasing frequency. This optimum piezoelectric performance was explained in terms of the highest crystallinity, β-phase content, and dielectric properties at the specific BTO content. The optimum PENG coupled with a capacitor and several light emitting demonstrated that it is possibly used to supply power with large energy storage capability of 470 µJ with a 1 µF capacitor for 3 min. This PENG of improved performance is promising as a supply power for a self-powered microelectronics because it has additional advantages of facile fabrication and coating a large area.

Composite design of two-dimensional inorganic nanosheets for flexible energy storage capacitors

We present a new approach for designing flexible energy storage capacitors using two-dimensional (2D) inorganic nanosheets. 2D dielectric Ca2Nb3O10 nanosheet and ferroelectric poly(vinylidene fluoride) (PVDF) were selected as model material systems. Langmuir–Blodgett deposition was utilized for layer-by-layer engineering of (Ca2Nb3O10/PVDF) nanocomposite films on an indium tin oxide (ITO)-coated polyethylene terephthalate (PET) substrate. Such a new composite design realized the simultaneous improvement of energy density (∼7 J cm−3) and efficiency (∼78 %) even in the ultrathin form (∼20 nm) on the ITO-coated PET substrate. Nanosheet-based flexible capacitors also maintained a stable performance even after 104 times bending cycles. These results indicate that our nanosheet approach is of technological importance for exploring new flexible dielectric capacitors.

Ultrasensitive and Cost-Effective Detection of Neuropeptide-Y by a Disposable Immunosensor: A New Functionalization Route for Indium-Tin Oxide Surface.

Neuropeptide Y (NPY) is one of the most abundant neuropeptides in the human brain, and its levels in the blood change in neurodegenerative and neuroimmune disorders. This indicates that NPY may serve as a diagnostic and monitoring marker for associated disorders. In this paper, an electrochemical immunosensor was created to detect NPY biomarkers using a novel immobilization technique. The proposed biosensor system enables accurate, specific, cost-effective, and practical biomarker analysis. Indium tin oxide-coated polyethylene terephthalate (ITO-PET) sheets were treated with hexamethylene diisocyanate (HMDC) to covalently immobilize antibodies. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques were used to analyze each step of the biosensors. The proposed NPY biosensor has a broad linear detection range (0.01-100 pg mL-1), a low limit of detection (LOD) (0.02968 pg mL-1), and a low limit of quantification (LOQ) (0.0989 pg mL-1). Atomic force microscopy (AFM) was used to support in the optimization process, study the surface morphology, and visualize it. Studies of repeatability, reproducibility, storage, and Kramers-Kronig transformation were conducted during electrochemical characterization. After analytical experiments, the biosensor's responses to human serum samples were evaluated. According to the obtained data, the error margin is small, and the created biosensor offers a great deal of promise for the clinical measurement of NPY.

Floating perovskite-BiVO4 devices for scalable solar fuel production.

Photoelectrochemical (PEC) artificial leaves hold the potential to lower the costs of sustainable solar fuel production by integrating light harvesting and catalysis within one compact device. However, current deposition techniques limit their scalability1, whereas fragile and heavy bulk materials can affect their transport and deployment. Here we demonstrate the fabrication of lightweight artificial leaves by employing thin, flexible substrates and carbonaceous protection layers. Lead halide perovskite photocathodes deposited onto indium tin oxide-coated polyethylene terephthalate achieved an activity of 4,266 µmol H2 g-1 h-1 using a platinum catalyst, whereas photocathodes with a molecular Co catalyst for CO2 reduction attained a high CO:H2 selectivity of 7.2 under lower (0.1 sun) irradiation. The corresponding lightweight perovskite-BiVO4 PEC devices showed unassisted solar-to-fuel efficiencies of 0.58% (H2) and 0.053% (CO), respectively. Their potential for scalability is demonstrated by 100 cm2 stand-alone artificial leaves, which sustained a comparable performance and stability (of approximately 24 h) to their 1.7 cm2 counterparts. Bubbles formed under operation further enabled 30-100 mg cm-2 devices to float, while lightweight reactors facilitated gas collection during outdoor testing on a river. This leaf-like PEC device bridges the gulf in weight between traditional solar fuel approaches, showcasing activities per gram comparable to those of photocatalytic suspensions and plant leaves. The presented lightweight, floating systems may enable open-water applications, thus avoiding competition with land use.

Influence of electrochemical co-deposition of bimetallic Pt–Pd nanoclusters on polypyrrole modified ITO for enhanced oxidation of 4-(hydroxymethyl) pyridine

Bimetallic Pt–Pd nanoparticles were dispersed on polypyrrole coated indium-tin oxide coated polyethylene terephthalate sheets (ITO-PET sheets). The excellent filming property of pyrrole gives a high porous uniform active area for the proper adsorption of bimetallic transition metal nanoparticles. Electrochemical behavior of the modified electrodes was determined using cyclic voltammetry and impedance studies. The physicochemical properties of the modified electrodes were analyzed by scanning electron microscopy, X-ray diffraction spectroscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. To study the electrochemical oxidation of 4-(hydroxymethyl) pyridine in the presence of sodium nitrate in aqueous acidic medium, the modified electrode was used. It is evident from the study that the modified electrode shows better electrochemical activity towards the oxidation of 4-(hydroxymethyl) pyridine.

Fabrication of graphene\u2013ZnO heterostructure-based flexible and thin platform-based UV detector

This work presents the performance evaluation of Graphene/ZnO Schottky junctions grown on flexible indium tin oxide (ITO)-coated polyethylene terephthalate (PET) substrates. The fabricated structures include chemical vapour deposition grown graphene layer on ITO-coated PET substrates. Polymethyl methacrylate assisted transfer method has been employed for the successful transfer of graphene from Cu substrate to PET. The smaller D-band intensity (1350 cm−1) compared to G-band (1580 cm−1) indicates good quality of carbon lattice with less number of defects. High-quality ZnO has been deposited through RF sputtering. The deposited ZnO with grain size 50–95 nm exhibited dislocation densities of 1.31270 × 10–3 nm−2 and compressive nature with negative strain of − 1.43156 GPa. Further, the electrical and optical characterization of the devices has been done through device I–V characterization and UV detection analysis. The UV detection capability of the device has been carried out with the aid of a UV-lamp of 365 nm wavelength. The fabricated graphene/ZnO photodetector showed good response to UV illumination. The device performance analysis has been done through a comparison of the device responsivity and detectivity with the existing detectors. The detectivity and responsivity of the fabricated detectors were 7.106 × 109 mHz1/2 W−1 and 0.49 A W−1, respectively.

Chemiresistive sensors based on Dodecyl benzene Sulfonic acid doped Polypyrrole and Reduced Graphene Oxide for nitrogen oxides

A new series of polypyrrole doped with n-dodecylbenzene sulphonic acid/reduced graphene oxide (PPy-DBSA/rGO) nanocomposite was electrodeposited on Indium tin oxide coated Polyethylene terephthalate (ITO/PET) flexible substrate by electrochemical route using the chronoamperometric technique. As-prepared for testing of chemiresistive properties against the detection of nitrogen dioxide (NO2) vapors at room temperature. The sensitivity and reactivity of the composite toward NO2 was evaluated. The recorded morphological and structural data confirmed that the PPy-DBSA/rGO forms a homogeneous nanocomposite. The optimal NO2 sensing properties have been revealed by the PPy-DBSA/rGO in terms of response (43%), response time (30.25 s), the detection limit (1ppm), and reproducibility. Furthermore, Results showed that the doped by sulfonic acid improved both the sensitivity and the reactivity of our produced nanocomposite toward NO2. Due to the strong interactions between the NO2 gas molecules and the rGO was dramatically enhanced the electronic properties of these nanocomposites. These striking characteristics of the newly developed nanocomposites make them very suitable to be used as NO2 gas sensor.

Multi-layered thin film nanocomposite MoS2@MoO2/MWCNP/ITO-PET: Electrochemical approaches for synthesis and structural characterizations

A shell@core nanostructure of MoS2@MoO2 on multi-walled carbon nanotubes paper (MWCNP) is fabricated by a two-step electrochemical process. Consecutively, electrophoretic deposition (EPD) and galvanostatic deposition (GSD) techniques are applied to deposit MWCNP on indium tin oxide coated polyethylene terephthalate (ITO-PET) film, then, to form MoS2@MoO2 on the surface of MWCNP. Raman spectra and XRD pattern of MWCNP/ITO-PET and MoS2@MoO2/MWCNP/ITO-PET thin films confirm EPD retains the original structure of MWCNTs as well as GSD successfully generates amorphous MoS2@MoO2 as skin of MWCNP. In EPD process, MWCNT-COOH with high defect density are preferred to deposition on ITO-PET electrode as well as MoS2@MoO2 reduces defect on sidewall of MWCNTs in GSD process. The XRD patterns confirms the orthorhombic and hexagonal structure of MoO2 and MoS2, respectively. The thickness of MoS2@MoO2 skin measured on TEM images is about 13–15 nm, while the planes distance measured on HRTEM is about 3.8 Å. Combination of characterization shows the mechanism leading to formation of MoS2@MoO2 nano-trail and nano-onion on body and end of MWCNTs, respectively, according defect density of the position. Thence, the two-step electrodeposition holds great potential due to its ability to rapidly produce large-area thin films as well as control nanostructures of materials.

Correction to: Structural and optical analysis of Ag nanoparticle-assisted and vertically aligned TiO2 nanowires for potential DSSCs application

In this work, vertically aligned TiO2 nanowires (TiO2-NWs) and Ag nanoparticle (Ag-NP)-assisted and vertically aligned TiO2 nanowires (TAT-NWs) were deposited on glass and flexible polyethylene terephthalate (PET) substrates using the glancing angle deposition (GLAD) technique. The morphology and structural analysis of the samples manifest successful deposition of vertically aligned TiO2-NWs and TAT-NWs. The high-resolution transmission electron microscopy (HR-TEM) image of TiO2-NWs shows the polycrystalline nature. Further, the X-ray diffraction (XRD) result confirms the polycrystalline nature of both the TiO2-NW and TAT-NW samples. Besides, HR-TEM image confirms the presence of small crystal grains of Ag-NPs at the mid of the annealed TAT-NWs. It is evident from the selected area electron diffraction (SAED) analysis of TiO2-NWs and annealed TAT-NWs that the crystallinity of TiO2 present in the annealed TAT-NWs improves after annealing. The absorption spectrum analysis of TAT-NWs deposited on glass substrate shows enhances absorption peak in the visible region with a maximum peak at ~ 450 nm wavelength compared to the TiO2-NWs, which may be attributed to the surface plasmon resonance (SPR) effect of Ag-NPs. Further, it is interesting to observe that the TAT-NWs deposited on PET substrate show further absorption enhancement in the UV and visible regions. In addition, the photoluminescence (PL) analysis reveals that the band gap of TiO2-NWs is ~ 3.12 eV. Therefore, the proposed method of fabricating TAT-NWs on glass and flexible ITO-coated PET substrates using the GLAD technique may be applicable for developing novel photoanode for dye-sensitized solar cells (DSSCs) and other optoelectronic applications.

Designing of 0D/2D mixed-dimensional van der waals heterojunction over ultrathin g-C3N4 for high-performance flexible self-powered photodetector

Mixed-dimensional 0D Bi QDs coated 2D g-C 3 N 4 NSs van der Waals heterojunction (g-C 3 N 4 @Bi) is designed and applied for fabricating flexible self-powered photodetector. • Mixed-dimensional 0D Bi QDs coated 2D g-C 3 N 4 (g-C 3 N 4 @Bi) heterojunction is prepared. • g-C 3 N 4 @Bi shows accelerated charge transfer and suppressed carrier recombination. • g-C 3 N 4 @Bi-based flexible photodetector shows self-powered photodetection capability. • The prepared photodetector exhibits good long-term stability (over 90 days). Mixed-dimensional van der Waals heterojunctions have attracted a great deal of attention due to their excellent photoelectric conversion capability, which have been widely applied for self-powered photoelectrochemical (PEC)-type devices as the growing demands of clean energy, environmental governance and protection, and the underwater communications. In this work, 0D Bismuth quantum dots (Bi QDs) encapsulated 2D g-C 3 N 4 nanosheets (g-C 3 N 4 @Bi) mixed-dimensional heterojunctions were prepared and spined on ITO-coated polyethylene terephthalate (PET) substrate for working as self-powered PEC-type photodetector (PD). Density functional theory calculations evidenced the successful construction of a type II van der Waals heterojunction between g-C 3 N 4 and Bi as well as its enhanced optoelectronic characteristics. Benefiting from the superior properties of g-C 3 N 4 @Bi, the as-prepared PD exhibits a high photocurrent of 5.02 μA cm −2 , a responsivity of 2843.14 μA W −1 , and a specific detectivity of 2.25 × 10 11 Jones at 0 V. Furthermore, the PD exhibits self-powered capability after 1000 cycles of bending, and the stable and repeatable ON/OFF signals can be detected over 90 days, indicating the excellent long-term stability and the potential of g-C 3 N 4 @Bi-based PD in practical applications.

Adsorption effect of NO2 on ZnO (100 nm) nanowires, leading towards reduced reverse leakage current and voltage enhancement

Here, we report the adsorption effect of NO2 on ZnO (100 nm) nanowires. We have studied the effect of adsorbed NO2 molecules on ZnO nanowire-based energy harvester for an exposure time of 1, 2, 3, 4, 5 and 6 h in a sealed chamber at 50 ppm which yielded piezoelectric voltage of 543.6 mV, 834.6 mV, 1.071 V, 1.78 V, 1.969 V and 2.835 V, respectively. We have thoroughly investigated the behaviour of ZnO nanowires in the presence of NO2 and observed a maximum output piezoelectric voltage of 2.835 V with a power density 158.2 mW cm−2. This is the first time that ZnO-based piezoelectric energy harvester is being used for the voltage enhancement in the presence of NO2. We have used vertically integrated nanowire generator (VING) structure. X-ray diffraction pattern revealed the growth orientation of ZnO nanowires were along the c-axis from the substrate. ZnO nanowires were grown on indium tin oxide-coated polyethylene terephthalate substrates via a hydrothermal route. Surface morphology has been examined by scanning electron microscopy images and diameter of ZnO nanowires was found to be around 100 nm. Piezoelectric voltage has been generated by the VING by applying minute external force of ~50 nN. Periodic output voltage peaks were being measured by picoscope 5204.

Photonic Thin Films Assembled from Amphiphilic Cellulose Nanofibrils Displaying Iridescent Full-Colors.

Self-assembly of nanoparticles (NPs) to form structural colors offers promising opportunities for developing electronic, optoelectronic, and magnetic devices. In this regard, we reported co-assembly of cellulose nanofibrils (CNFs) and graphene to produce colored thin films. We demonstrated that biomimetic iridescent "peacock feather"-like full-color thin films can be generated by simple evaporation of aqueous suspensions on a surface tension confined, optically symmetric indium tin oxide-coated polyethylene terephthalate substrate. Amphiphilic CNFs serve dual functions to attract hydrophobic graphene via van der Waals interactions and to disperse hydrophilically and anionically CNF-tethered graphene while regulating surface tension to induce capillary and Marangoni flows in the force fields and construct thickness variation during dewetting. These CNF-graphene thin films exhibit full-color patterns and function as tunable light and moisture actuators. This approach has high potential to be applied to assemble other metal or metal oxide NPs for fast, simple, and robust fabrication without involving any complex lithography and external fields.

Investigating Catechol Surface Modification of TiO2 for the Development of High Performance Photoelectrochemical Biosensors

DNA biosensors are chemical sensors which are used to detect concentrations of specific DNA sequences or register DNA related biological events. There is significant interest in research into the design and optimization of DNA biosensors as they allow for rapid detection of cancers and infectious diseases 1,2. Photoelectrochemical (PEC) techniques can be applied to achieve high performance DNA biosensors with low cost and ultra-sensitivity. In this work, we explored the surface modification of TiO2 nanoparticles (NP) with various catechol molecules and used them to fabricate photoelectrodes for signal-off PEC DNA biosensors. Catechol modification provided dual functionality to the TiO2 NP photoelectrodes: it enhanced their PEC response and provided a molecular linker for attaching probes that capture target DNA.The surface modification of TiO2 NPs was done by adding aqueous solutions of catechol molecules to a suspension of TiO2. Adsorption of catechol on TiO2 took place very rapidly, indicated by a quick change in the colour of the suspension. The catechol-modified TiO2 suspensions were dropdeposited on indium tin oxide coated polyethylene terephthalate (ITO/PET) substrates and oven baked to produce photoelectrodes for the PEC DNA biosensor. Seven catechol molecules were used for surface modification: Caffeic acid (CA), 3,4-Dihydroxybenzaldehyde (DHBA), 3,4-Dihydroxybenzoic acid (DHB), 3,4-Dihydroxy-L-phenylalanine (DOPA), 3,4-Dihydroxyphenylacetic acid (DHPL), 2,3,4-Trihydroxybenzaldehyde (THBA), 2,3,4-Trihydroxybenzoic acid (THB). The photoelectrodes were optically characterized via ultraviolet/visible (UV/vis) spectroscopy and incident photon-to-electron conversion efficiency (IPCE). Additionally, the PEC current of the photoelectrodes were measured using chronoamperometry under white light excitation.Compared against unmodified TiO2, the UV/Vis spectroscopy and IPCE displayed increased light absorption in the visible range and red-shifting for the catechol-modified TiO2 photoelectrodes. This correlated to a great improvement in photocurrent generation. CA-modified TiO2 resulted in the largest increase in photocurrent, over 20 times from the unmodified TiO2 and therefore it was used as the basis for our PEC DNA biosensor. Single stranded DNA (ssDNA) probes were deposited onto the photoelectrodes, followed by target ssDNA deposition. The difference in PEC current after probe deposition and target deposition indicated the concentration of target DNA. A calibration curve was plotted with PEC current density as a function of target DNA concentration, which decreased logarithmically and ranged from 100 nM – 100 fM. A limit of detection (LOD) of 2.38 pM was estimated at a signalto-noise ratio of 3Sx/y (where Sx/y is the root-mean-square error (RMSE)).It is evident from our investigation that functionalizing TiO2 with catechol ligands greatly improves its optical properties which lead to a greater PEC current generation. In particular, high PEC current resulting from the combination of CA and TiO2 can form the basis for high-performance signal-off PEC DNA biosensors with a high dynamic range and low LOD. 1. Beltrán, A. P. & García, M., DNA biosensors and biomarkers to cancer detection. International Journal of Biosensors and Bioelectronics, 4(1), 20-21 (2018)2. Chua, A., Yean, C. Y., Ravichandran, M., Lim, B. & Lalitha, P., A Rapid DNA Biosensor for the Molecular Diagnosis of Infectious Disease. Biosensors and Bioelectronics, 26(9), 3825-3831 (2011)

Optically Transparent Protective Coating for ITO-Coated PET-Based Microwave Metamaterial Absorbers

In spite of indium tin oxide (ITO)-coated polyethylene terephthalate (PET) sheets being a thriving candidate for flexible and transparent microwave metamaterial absorbers (MMAs), these materials are not robust under severe environmental and handling conditions. The ITO coatings are brittle and have poor scratch resistance when coated over flexible PET sheets; hence, their electrical performance degrades in time. Here, thin films of polyvinyl butyral (PVB) and also its composite with 3-aminopropyltriehoxysilane (APTES) processed at room temperature have been investigated as protective coatings over ITO-coated PET sheets, particularly for MMA application. Prior to coating, the effectiveness of various surface treatments to increase the ITO's wettability by exposure to UV light, chemicals, and air plasma was demonstrated by contact angle measurements. Furthermore, the consequences of surface treatments on the adhesion of the protective coatings to the ITO surface were studied using microindentation, pencil scratch test, ultrasonication test, water soak test, and shower test. Measurements of microwave absorption of the coated and uncoated substrates (PET and ITO-PET) over the X-band (8.2-12.4 GHz) showed a similar electromagnetic (EM) response approximately. Finally, free-space measurements of the MMA before and after PVB coating at its top and bottom were compared from 4 to 16 GHz, and the maximum EM absorption was found to have increased from 95.94% to 98.56%. Optical transparency of coated ITO-PET was quantified by measuring the optical transmittance at 632.8-nm wavelength using red laser and found to be equal to 68.9 ± 6.9. The mechanical strength of the developed coatings is analyzed by nanoindentation technique by obtaining values of hardness and elastic modulus.

Ion beam modification of polyaniline: Optical and electrical properties of Cu+ ion implanted thin films

Ion implantation of thin nanometre scale films is believed to facilitate better control of the material modification process in thin films when compared to mainstream chemical and electrochemical methods. In this work emeraldine base polyaniline (PANI) films on Indium Tin Oxide coated Polyethylene Terephthalate (ITO/PET) substrates were implanted with 50 keV Cu+ ions at liquid nitrogen temperature to fluences between 0.5 × 1016 and 5.0 × 1016 ions/cm2 to form Cu-PANI nanocomposite sublayer regions in the films. UV–vis, PL and I-V measurements were used to investigate changes in optical and electrical properties of the films post ion implantation. UV–vis data shows red shifting of the optical band gap as a function of fluence from 3.12 eV down to 1.41 eV. At higher fluences Local Surface Plasmon Resonance (LSPR) effects are observed due to formation of Cu nanoparticles ((NPs) in the PANI matrix. Photoluminescence spectra show an increase in the emission peak intensity with fluence, suggesting a corresponding increase in the number of available charge carriers due to radiation induced carbon clustering. This is corroborated by I-V data, which shows a decrease in the DC resistance of the films as a function of fluence.

Bending fatigue damage reduction in indium tin oxide (ITO) by polyimide and ethylene vinyl acetate encapsulation for flexible solar cells

Hybrid organic-inorganic perovskites hold tremendous promise for next-generation portable power source applications. However, the device reliability under severe mechanical deformations is limited due to the use of brittle indium tin oxide (ITO). In the current study, we have attempted to enhance the bendability of the device by employing an encapsulation on the ITO coated polyethylene terephthalate (PET) substrate. The aim of this encapsulant buffer layer is to shift the location of the maximum bending stresses away from the ITO as well as provide barrier properties against the environment. Ethylene-vinyl acetate (EVA), as well as Polyimide (PI) films, have been used as encapsulating materials with the aim to shift the location of the neutral axis to the ITO. Finite element analysis has been done to evaluate the principal stresses generated in ITO during monotonic bending under different modes of bending, the thickness of encapsulant layers as well as radii of bending. The effect of the number of bending cycles, mode of bending as well as the bending radii on the conductivity of the ITO have been studied experimentally. A large change in resistance of ITO film has been used as a metric to determine the failure of the ITO film. Samples encapsulated with an optimum thickness of PI shows a significant reduction in percentage change in resistance as compared to raw samples for both cases of bending, while EVA encapsulated samples hardly show any improvement. Moreover, both the modulus and thickness of an encapsulant play an important role in enhancing the bendability.

Experimental analysis of interfacial shear stress and electrical resistance of indium tin oxide-coated polyethylene terephthalate films for a whole folding test

The purpose of this study is to analyze the performance of the flexible conductive substrate by interfacial shear stress. This study performed automatic liquid-crystal modulating common-path interferometry (LMCI) optical inspections on 125-µm polyethylene terephthalate (PET) substrates having indium tin oxide (ITO) coating thicknesses of 80 nm, 160 nm, and 230 nm. The nonlinear characteristic of the stress-optical coefficient of the ITO material is obtained using LMCI. To validate the performance of the flexible conductive substrate, this study has utilized an automatic sliding-folding testing platform (ASTP) for a whole-folding test. Eventually, this study successfully has utilized interface shear stresses to validate the performance of the flexible conductive substrate depended on the different thicknesses of the conductive layers for whole-folding test by using LMCI and ASTP. According to the measurement results, as the folding radii decrease and the ITO thicknesses of ITO-coated PET substrates increase, the changes of interfacial shear stresses increase in compressive direction and the change-rates of electrical resistance of ITO-coated PET substrate also increase. Therefore, the interfacial shear stress measurement and analysis results depicted on flexible conductive substrates provide a validation for improving the manufacturing process and for reducing process residual stresses.