Search

In recent era of modern and bendable technology, energy dearth arises as a paramount subject around the globe with a dire demand of flexible and lightweight energy storage devices. This study targets fabrication of reduced graphene oxide (rGO) and utility of abundantly available, cost effective, and environment friendly lignocelluloses (LC) fibers extracted from Carica papaya source, as a binder to bind active material (rGO) as robust and compact paper sheet. Fabricated samples were analyzed by X-ray diffraction for crystallographic analysis, Scanning electron microscopy, Transmission electron microscope for morphology, Fourier transform infrared spectroscopy for structural bonding, and Raman spectroscopy for vibrational modes. Robust and bendable rGO/LC paper electrode was tested for energy storage application by employing in different characterizations, i.e., cyclic voltammetry for capacitive behavior, galvanostatic charge–discharge for symmetric EDLC, and electrochemical impedance spectroscopy for resistive charge kinetics, respectively. rGO/LC composite sheet employed as working electrode in 3-electrode CV measurements and revealed specific capacitance of 591 F/g at a scan rate of 5 mV/s by keeping the undistorted shape of voltammograms at higher scan rates which present it as a suitable candidate for modern flexible and energy storage devices. rGO/LC-based symmetric cell revealed the highest specific capacitance of 228 F/g at applied current density of 0.1 A/g, the energy density of 6.3 Wh/kg, and power density of 129 W/kg, respectively. rGO/LC-based symmetric cell confirmed the cycling stability by revealing capacitance retention of 82% after 200 cycles. It can conclude that biomass-based rGO paper sheet can be a potential candidate as environmentally safe with remarkable electrochemical activity in energy storage applications.

Manipulation of materials at nanoscale provides many new and enhanced properties to be utilized for multifaceted applications, which was not possible before. In this study, we fabricated Bi2WO6/rGO composites using hydrothermal method. The obtained composites were then examined using different analytical techniques such as XRD, SEM, TEM, FTIR, XPS, BET, and AFM. Their catalytic properties were assayed by carrying out the degradation of organic dye Rhodamine B (RhB) and employed as a hole transport layer (HTL) in the perovskite solar cells. The fabricated nanocomposites were able to degrade 98% of dye solution within 4 h. The improved photocatalysis is attributed to a large surface area ~86.06 m2/g with pore size 7.812 nm and enhanced separation of electron-hole pair charges due to rGO sheets. The open-circuit voltage was increased up to 0.94 V when composite materials were used as HTL. The power conversion efficiency (PCE) of the device was enhanced to 11% because of the improvement in the interface quality between HTL and the perovskite layer. It is conceived that the fabricated nanomaterial may show excellent potential in smart solar cell applications.

Tungstate nanorods (WO3 -NRs) were synthesized by a facile hydrothermal method using sodium tungstate as a precursor while sodium sulfate and hydrochloric acid were used as stabilizing agents. Scanning electron microscopy (SEM) images showed outstanding growth of WO3-NRs with uniform surface morphology. The X-ray diffraction (XRD) analysis confirmed the purity and crystalline nature of the synthesized material. The material was further characterized by different tools such as TEM, EDX, FTIR, XPS, BET, and Raman spectroscopy. For the electrochemical response of WO3-NRs, cyclic voltammetry measurements were performed for the detection of vitamin C (ascorbic acid). The designed sensor shows a limit of detection of 0.56 µM and higher selectivity in the presence of its structural and functional analogs such as uric acid and lauric acid. Improved sensing properties of WO3-NRs are attributed to the synergistic effects involving the quantum effect, high surface area, fast electron transfer, and highly ordered 1-D nanostructure. Among them, the highly arranged 1-D growth of WO3 nanorods has a greater impact on the efficiency of the biosensor. These results provide a new insight for the synthesis of 1-D nanostructures of transition metal oxides for contributions in sensor devices, solar cells, and capacitor applications.

Nano-food packaging, the emergence of latest technology based on nanomaterials, created enormous trust to the synthesis of novel packaging incorporated by zinc oxide nanoparticles (ZnO-NPs) in polylactic acid (PLA) polymer. The morphology and structure of biogenically fabricated ZnO-NPs by aloe barbadensis leaves extract were analyzed by X-ray diffraction, scanning electron microscopy and Fourier transforms infrared spectroscopy. The fabricated ZnO-NPs were hexagonal in shape and 36.5 nm in size. The zinc oxide nanoparticles at concentration of 0.4% (w/w) and 4% (w/w) are incorporated in polylactic acid (PLA) by solution casting method. Loading of zinc oxide nanoparticle in PLA improved stability, film thickness and elongation. The Vitis vinifera fruit packed in the biofilm was observed for appearance, taste and freshness during ambient storage. ZnO-NPs/PLA packed fruit samples retained their original taste and freshness for 15 days in comparison with the reference samples packed in ZnO-NPs/ PLA (4%) at 400C. The biofilm did not affect the fruit Vitis vinifera quality attributes. The decay content, color change, browning index, gases and metal accumulation observations for Vitis vinifera fruit packed in ZnO-NPs/ PLA (4%) exhibited marvellous results. There were no significant differences between the materials tested (p > 0.05). Intercalation of ZnO-NPs was involved in the form of fillers in PLA by solvent casting method for shelf life augmentation of the selected delicate fruit, Vitis vinifera.

We report the influence of reactive oxygen (O2) and argon (Ar) plasma based ITO:Zr bi-layers for silicon heterojunction (SHJ) solar cells. The purpose of reactive O2 sputtered ITO:Zr was to improve the Hall mobility and work function while the Ar based ITO:Zr films play an important role to maintain good electrical characteristics. The thickness of reactive O2 based ITO:Zr films was fixed at 15 nm while Ar based films was varied from 65 to 125 nm, respectively. ITO:Zr bi-layers with the thickness of 15/105 nm deposited by O2 and Ar plasma, respectively, showed lowest resistivity of 2.358 × 10−4 Ω cm and high Hall mobility of 39.3 cm2/V · s. All ITO:Zr bi-layers showed an average transmittance of above 80% in the visible wavelength (380–800 nm) region. Work function of ITO:Zr bi-layers was calculated from the X-ray photoelectron spectroscopic (XPS) data. The ITO:Zr work function was enhanced from 5.3 eV to 5.16 eV with the variation of ITO:Zr bi-layers from 15/65 to 15/125 nm, respectively. Front barrier height in SHJ solar cells can be modified by using TCO films with high work function. The SHJ solar cells were fabricated by employing the ITO:Zr bi-layer as front anti-reflection coating. The SHJ solar cells fabricated on ITO:Zr bi-layer with the thickness of 15/105 nm showed the best photo-voltage parameters as; Voc = 739 mV, Jsc = 39.12 mA/cm2, FF = 75.97%, η = 21.96%.

Light-trapping phenomenon is limited due to non-uniform surface structure of transparent conducting oxide (TCO) films. The proper control of surface structure with uniform cauliflower TCO films may be appropriate for efficient light trapping. We report a light-trapping scheme of SF6/Ar plasma-based textured glass surfaces for high root-mean-square (RMS) roughness and haze ratio of ITO films. It was observed that the variation in Ar flow ratio in SF6/Ar plasma during the inductive coupled plasma-reactive ion etching (ICP-RIE) process was an important factor to improve the haze ratio of textured glass. The SF6/Ar plasma textured glass showed low etching rates due to the presence of various metal elements, such as Al, B, F, and Na. The ITO films were deposited on SF6/Ar plasma-textured glass substrates showed the high RMS roughness (433 nm) and haze ratio (67.8%) in the visible wavelength region. The change in surface structure has a negligible influence on the electrical properties of ITO films. The TCO films deposited on periodic textured glass surfaces with high RMS roughness and haze ratio are proposed for high-efficiency amorphous silicon (a-Si) thin-film solar cells.

In the new era of modern flexible and bendable technology, graphene-based materials have attracted great attention. The excellent electrical, mechanical, and optical properties of graphene as well as the ease of functionalization of its derivates have enabled graphene to become an attractive candidate for the construction of flexible devices. This paper provides a comprehensive review about the most recent progress in the synthesis and applications of graphene-based composites. Composite materials based on graphene, graphene oxide (GO), and reduced graphene oxide (rGO), as well as conducting polymers, metal matrices, carbon-carbon matrices, and natural fibers have potential application in energy-harvesting systems, clean-energy storage devices, and wearable and portable electronics owing to their superior mechanical strength, conductivity, and extraordinary thermal stability. Additionally, the difficulties and challenges in the current development of graphene are summarized and indicated. This review provides a comprehensive and useful database for further innovation of graphene-based composite materials.

The exploration of electrode functional materials for supercapacitors may bring a revolution to energy storage devices to boost the portable industry. Herein, lanthanum sulfide nanorods and reduced graphene oxide (rGO)–templated lanthanum sulfide nanorods have been synthesized using the hydrothermal process. Structural, morphological, and compositional analyses were conducted using X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The specific surface area has been measured using the Brunauer–Emmett–Teller technique. Individual lanthanum sulfide and rGO-templated lanthanum sulfide showed the morphology of nanorods. Cyclic voltammetry tests predicted the pseudocapacitive nature of the lanthanum sulfides for supercapacitor applications. The rGO effectively improved the electrochemical characteristics of the lanthanum sulfide, which might be due to the facilitation of charge carriers through nanorods, as the rGO-templated lanthanum sulfide nanorod showed a specific capacitance of 75.17 F/g at a scan rate of 30 mV/s evidenced by cyclic voltammetry (CV) curves. The rGO significantly increased the discharge time from 60 to 188 s, specific capacitance from 20.32 to 34.12 F/g, and energy density from 572 to 1185 mW/kg compared to individual lanthanum sulfide nanorods as seen by the galvanostatic charge/discharge profile. The rGO-templated lanthanum sulfide nanorods showed a power density of 255.20 W/kg at a high current density of 0.2 A/g and a specific capacitance retention up to 91.60% for 2000 cycles at scan rate of 20 mV/s. Symmetric cell exhibited the specific capacitance of 94.45 F/g, energy density of 6.43 Wh/kg at the current density of 0.05 A/g, and power density of 351.25 W/kg at the current density of 0.2 A/g. The test results indicate that the use of rGO is effective in improving the electrochemical characteristics of lanthanum sulfide nanorods for supercapacitor applications.

Priming effect of silicon sources (silica gel and sodium silicate) on the seeds of four wheat cultivars of Balochistan was studied to determine their effectiveness in increasing relative salt tolerance. The study depicts that all priming treatments of silicon sources (except sodium silicate 2%) enhanced germination and reduced mean germination time (MGT) of seeds in comparison to the control i.e. hydropriming. After germination, the young seedlings were grown in hydroponics in Hoagland’s culture solution under controlled conditions in non-saline and saline (100 mM NaCl) environments. All the growth parameters (root and shoot length, fresh and dry weights of plants and chlorophyll content of leaves) severely reduced in hydroprimed seeds under saline environments, although increased by priming seeds with silicon sources. Thus silica compounds have potential effects to break the seed dormancy and improve the growth of wheat under salinity stress.

In this modern age of technology, flexible, light-weight, environment-friendly and low-cost electrodes are vastly feasible for applications in energy storage devices and disposable electronics. This study presents a comprehensive report on the morphological, dielectric, and impedance characteristics of lignocellulose (LC) fibers, PbO2, and LC/PbO2 sheets. The dielectric analysis shows that the dielectric constant depends on space charge polarization in the case of LC/PbO2 composite sheets. It can be concluded from impedance spectroscopy results that LC fibers show semiconductor-like behavior and fibers appear to consist of one type of dielectric species whose impedance behavior can be modeled by a parallel combination of a resistor and a capacitor. However, the impedance response of PbO2 consists of two types of dielectric species, which can be identified as grains and grain boundaries, both of which show a small temperature dependence. The impedance behavior of LC/PbO2 composite is different in comparison to individual LC fibers and PbO2. The presented study also reveals that impedance parameters of fabricated LC/PbO2 composites are temperature-independent, which might be due to counteracting the characteristics of LC fibers and PbO2 particles. This temperature-independence of the composite is important for their use in applications in flexible devices.

Unconventional and alternative resources are proved incredibly useful for flexible and bendable energy storage devices to meet the demand of modern disposable and bendable technology. Nickle hydroxide [Ni(OH)2] based composites are considered as high-performance electrodes for supercapacitor and batteries applications due to high specific capacitance at higher scan rates. This study presents the fabrication Ni(OH)2 and incorporation of lignocelluloses(LC) fibers as binders to address the inherent rigid structure. Furthermore, electrically conductive properties are address by synthesis of composites with Polypyrrole and Polyaninline. X-Ray diffraction (XRD) results confirm the successful formation of nickel hydroxide whereas scanning microscopy results (SEM) reveal the nanoparticle morphology. Incorporation of LC fibers within Ni(OH)2 particles presented as compact and flexible composite paper electrodes which can be cut with help of scissor in any shape for bulk use. Fourier Transform Infrared (FTIR) confirmed the composite formation and cyclic voltammetry (CV) measurements were performed for all the fabricated samples to observe the electrochemical kinetics by which the best specific capacitance is shown by Ni(OH)2/PPy/LC i.e. 630 Fg−1. These fabricated composites can be used further as flexible electrodes in energy storage applications because of enhanced electrochemical properties. Presented flexible Ni(OH)2 based paper sheets will be highly feasible for modern bendable and disposable energy storage devices due to light-weight and environmentally safe characteristics.

To meet the demand of modern flexible and disposable technology, directly collected lignocelluloses fibers and graphite composite are successfully fabricated with uniformly electrodeposited of thin layers of nickel, silver and nickel. These multilayers (Ni-Ag-Ni) were electrodeposited on lignocelluloses-graphite sheet by using three electrode setup at a constant reduction potential (−0.95 V) between the electrodes. Composition and nanostructures of these nanocomposites (LC-graphite-multilayers) were investigated by using energy dispersive x-ray spectrometry, field emission scanning electron microscopy, Raman spectroscopy, UV–VIS and impedance spectrometer. FE-SEM images revealed that Ni-Ag-Ni layers are uniformly integrated into LC-graphene matrix and EDX analysis confirmed the deposition of multilayers Ni and Ag. Dielectric analysis revealed the non-linear frequency dependent response of the multilayered deposited LC fibers based nanocomposite. Complex impedance spectroscopy analysis presented the multilayered deposited LC fibers based paper electrode for high-tech applications in optical and electronic devices.

Metal oxide based electrodes are attractive for energy storage applications with limited characteristics of flexibility due to inherent rigid structure. However, incorporation of flexible insulating matrix within metal oxide composites result in poor electrically conductive and energy storage characteristics. This study presents the fabrication of flexible MnO2 based composite electrodes prepared by incorporation of lignocelluloses (LC) fibers, directly collected from a self-growing plant, Monochoria Vaginalis. Furthermore electrodeposition of silver (Ag) nanoparticles was performed on LC/MnO2 in potentiostatic mode to address the electrically conductive characteristics. Morphology, structural, conductive and energy storage properties of fabricated electrodes are analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), impedance analyzer and potentiostat, respectively. SEM images clearly indicate the deposition of Ag nanoparticles on MnO2 nanorods embedded in LC fibers whereas FTIR results confirm the bonding of the functional groups. Cyclic voltammetry measurements showed efficient kinetics of LC/MnO2 after electrodeposition of Ag nanoparticles. The effects on electrical properties associated with blending MnO2 nanorods in lignocelluloses fibers and Ag deposition on MnO2 in LC/MnO2 are explored in wide frequency range between 10 Hz and 5 MHz. However, deposition of Ag nanoparticles on MnO2 nanorods surfaces acts as a conductive path and reduces the associated resistance. Incorporated flexibility in rigid structure of MnO2 and further improvements in conductive and energy storage characteristics will open the possibilities to be used as electrode in modern bendable energy storage devices.

Surface morphology induced electrical conductivity and specific surface area of a material play a significant role to facilitate electrochemical behavior for supercapacitor application. Therefore, the synthesis step for controlling such parameters becomes very imperative and challenging. Herein, a ZnS nanoweb is deposited directly onto Ni foam with a pre-deposited thin layer of hydrothermally prepared graphene oxide. The structure and surface morphology of the deposited ZnS is observed using XRD and SEM, respectively. The electrical conductivity of the graphene oxide supported ZnS nanoweb, determined using the four probes method, is 100.15 Scm(-1). The specific surface area is 104.42 m(2)g(-1) as determined by BET measurements. Pseudocapacitive behavior is monitored by cyclic voltammetry, and the excellent specific capacity of 3052 Fg(-1) has been found at a scan rate of 2 mVs(-1), while it is 2400.30 Fg(-1) according the galvanostatic charge-discharge profile at a current density of 3 mAcm(-2). Both values are significantly higher than those measured for bare GO or ZnS layers. The energy and power densities of GO supported ZnS nanoweb are determined in a three electrode setup, are 120 WhKg(-1) at 3 mAcm(-2) and 4407.73 Wkg(-1), respectively. In a symmetric two electrode setup, an energy density of 20.29 WhKg(-1) at 2 mAcm(-2) is observed. Hence, both symmetric and asymmetric measurements suggest that GO supported ZnS nanoweb can be applied as a suitable electrode for supercapacitors.

Graphene oxide based electrode materials show remarkable electrochemical properties due to the improved specific surface area and electrical conductivity for supercapacitor applications. Hydrothermally synthesized graphene oxide based aluminum sulfide nanowalls on nickel foam (NF) have revealed excellent pseudocapacitive behavior with the specific capacitance 2362.15 F g-1 at 2 mVs-1 as observed through cyclic voltammetry. The galvanostatic charge-discharge measurements confirmed a specific capacitance 2373.51 F g-1 at 3 mAcm−2. Hexagonal phase of the graphene oxide (GO) based Al2S3 nanowalls also showed good discharge time of 820 s and energy density 118.68 WhKg−1 at 3 mAcm−2. Moreover, the fabricated electrode material exhibited good power density 2663.58 W kg-1 at 20 mAcm−2. The impedance results also confirmed the pseudocapacitive characteristics and revealed weak contact and Warburg resistances for the electrode material in half cell. Hence, GO based Al2S3 nanowalls performed as a prominent electrode material for asymmetric supercapacitors. Additionally, electrode material also exhibited excellent symmetric behavior, which again suggested a good electrode structure for supercapacitor applications.

V2O3 samples were successfully prepared using [VOSO4·xH2O] as the starting material by a template-free hydrothermal method with the addition of KBrO3. The prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and cyclic voltammetry (CV). The XRD result shows the rhombohedral structure for V2O3 with an average crystallite size in the range of 22 nm. With the increase in reaction time (6–8 h), the morphology of the samples changes from nano-flower to nano-ribbons as indicated by SEM micrographs. FTIR spectrum shows that the band at 1286 cm−1, related to C–OH stretching and OH bending vibrations and indicate the presence of residual hydroxyl groups. The electrochemical measurements show an excellent storage response, kinetics and reversibility of the electrode material. Further, good rate capability of the materials was also observed.

Development of cost efficient, flexible and light weight paper electrodes for high-tech applications is high in demand in era of modern disposable technology. In this study α-MnO2 nanorods were fabricated through hydrothermal method by varying growth time and further combined with lignocelluloses fibers extracted from self growing plant, Monochoria Vaginalis. Crystal structure, morphology and thermal properties of MnO2 nanorods were characterized by X. Ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM) and Thermogravimetric Analysis (TGA), respectively. FESEM image analysis revealed the highest aspect ratio of 48.016 for 4 h treated MnO2 sample and high purity level was confirmed by XRD. MnO2 sample with high aspect ratio, relatively pure and larger yield was selected for incorporation of lignocelluloses fibers to fabricate flexible, light-weight and environmentally safe LC/MnO2 composite paper sheet. Furthermore, LC/MnO2 composite sheet was employed as working electrode in 2 M sodium sulfate electrolyte for cyclic voltammetry measurements. Presented LC/MnO2 composite sheet revealed specific capacitances 117, 59, 39, 25 and 23 F/g at scan rates of 5, 10, 20, 50 and 100 mV/s, respectively. Incorporation of LC fibers within MnO2 nanorods as binders will open the possibilities to fabricate the flexible paper electrode for application in supercapacitors and batteries due to facile synthesis, light-weight and environmentally friendly aspects.

Structural, morphological, dielectric and electrical properties of Zr1−xNixTiO4 (x = 0, 0.05, 0.10, 0.15 and 0.2) are studied in this work using X-ray diffraction, field emission scanning electron microscopy and impedance spectroscopic measurements, respectively. The compositions were prepared using sol–gel auto-combustion method and observed to possess the orthorhombic structure with a space group, Pnab 60. The Fourier transform infrared spectroscopy inveterated that the combustion was complete. Field emission scanning electron microscopic study reveals that the homogeneity and density of the particles increase with increasing doping concentration. Grain size increases with increasing Ni contents i.e. from 0.25 to 0.5 µm, mostly depicting irregular morphology. Energy dispersive X-ray technique confirmed the presence of Ni, Zr, Ti and O in the prepared materials. Dielectric parameters i.e. dielectric constant and loss decreases with increasing frequency. Conductivity increases with increasing Ni contents and with the increase in frequency. Complex impedance plot shows a single semicircle corresponding to ZrTiO4 and Ni-doped ZrTiO4 which determines the dominancy of grain boundary resistance at low frequency. Electric modulus reveals the real dielectric relaxation process.

In the era of modern disposable electronic technology, flexible substrate materials are excessive in demand due to foldable, bendable and stretchable choices. This paper reviews the research undertaken on flexible substrates particularly employed in high-tech applications of radio frequency and antenna design technologies. Irrespective of traditional applications, natural fibrils based substrates are considered most promising candidates as substrates for next-generation electronic applications due to abundant, low profile, light-weight, flexible and environment safe characteristics. This paper also presents a comprehensive study of the design and methods that have been applied to use mentioned materials in radio frequency applications. Several challenges are highlighted in the large-scale production and deployment of these technologies in real-world systems.

Owing to large specific surface area and high electrical conductivity, nanostructured electrodes exhibit improved electrochemical activity for supercapacitor applications. In the present study, structure and morphology of hydrothermally synthesized strontium sulfide and graphene oxide based Strontium sulfide nanorods have been investigated by using XRD and SEM, respectively. Introduction of graphene oxide thin film improves specific surface area and result in the excellent electrical conductivity of Strontium sulfide nanorods. Due to this, graphene oxide based strontium sulfide nanorods illustrate excellent specific capacitance and energy density of 1831.14 F g−1 and 91.56 WhKg−1, respectively, at the current density of 3 mAcm−2, as measured by employing three electrode galvanostatic charge discharge system. Moreover, electrode of graphene oxide based strontium sulfide nanorods also shows good electrochemical performance, according to the measurements by symmetric two electrode system. Energy and power density is measured as 10.55 WhKg−1 and 294.35 W kg−1, respectively. The excellent electrochemical performance of graphene oxide based strontium sulfide nanorods reveals its significance as nanostructured materials for supercapacitor applications.

In this research work, we have studied the effect of substitution of Sr on the structural, morphological and impedance spectroscopic properties of Zr1−xSrxTiO4 (x = 0, 0.05, 0.10, 0.15 and 0.2), synthesized using sol-gel auto-combustion technique. The X-ray diffraction confirmed the orthorhombic phase. The Fourier transform infrared spectroscopy spectra confirmed that no organic content was present in the sample. Field emission scanning electron microscopic analysis reveals that the particle size reduces from 125 nm to 15 nm. Energy dispersive X-ray technique confirmed the presence of Zr, Ti, Sr and O in the matrix. Dielectric properties are measured at room temperature in the frequency range of 20 Hz to 20 MHz by using the impedance analyzer. Dielectric parameters have been studied by using Koop's theory and Maxwell-Wagner's Model. AC conductivity increases with the increase in frequency and with increasing Sr contents. The impedance plot shows the dominance of grain boundary resistance. Dielectric relaxation process has been studied using Modulus plot.

Wide bandgap with low work function-based materials are widely used as an electron transport layer to achieve high efficiency in silicon heterojunction (SHJ) solar cells. We presented transparent Lithium fluoride (LiFx) films with a wide optical bandgap and various thicknesses for the applications of SHJ solar cells. The high-resolution transmission electron microscopic (HR-TEM) analysis was used to confirm the thickness of LiFx layers. The aluminium electrode's work-function was reduced because of the high dipole moment by the LiFx and lowers an energy barrier at back contact. Enhancement of quantum efficiency (QE) at longer wavelength regions and operating voltage was due to lower energy barrier height can improve the short-circuit current density (Jsc), open-circuit voltage (Voc), and hence solar cell efficiency. Thermally evaporated-based LiFx films showed an optical transmittance of 88 ~ 90% in the visible-NIR (380–1100) nm wavelength region. LiFx/a-Si:H(i)/c-Si/a-Si:H(i)/LiFx structure for 20 nm thick LiFx showed lifetime of 1129.73 μs and implied iVoc of 731.7 mV. SHJ solar cells were fabricated using various thicknesses 1, 10 and 20 nm, respectively. The SHJ solar cells fabricated on 20 nm thick LiFx film yield the maximum efficiency of 17.16% and was used for the baseline condition of simulations. The simulated performance of the SHJ solar cell was improved from 0.098 to 22.58% as a function of variable LiFx work function from 3.2 to 3.9 eV.

ZnO based nanostructure composites are attractive for high-tech applications of energy conversion and energy storage due to wide range in operating potential window. This study presents about fabrication of ZnO/MnO2 and ZnO/TiO2 composites via hydrothermal method in two consecutive steps. Furthermore lignocelluloses fiber directly collected form self-growing plant Monochoria Vagina, were incorporated in fabricated ZnO/MnO2 and ZnO/TiO2 composites for development of flexible and bulk paper composite electrode. The structural and morphological analysis were carried out using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), respectively. XRD analysis confirm the crystalline structures for ZnO/MnO2 and ZnO/TiO2 samples with crystallite size ∼62 nm and ∼63 nm, respectively. SEM images shows the sheet-like and nanorods morphology for ZnO and MnO2 nanostructures, respectively. Fourier Transform Infrared (FTIR) Spectroscopy absorbance spectrum reveal the composite formation of ZnO/MnO2/LC and ZnO/TiO2/LC as bulk paper electrodes whereas cyclic Voltammetry measurement showed the capacitive behavior of composite paper electrodes for the suitable applications in supercapacitors and batteries.

In era of modern technology, light-weight, flexible, low-cost and environmentally safe substrates/electrodes are highly feasible for application in disposable electronics and energy storage devices. This study presents morphological and dielectric characteristics of naked and polyaniline (PANI) coated lignocelluloses fibers, directly collected from self-growing plant, Typha Angustifolia. Impedance spectroscopy measurements performed in frequency range from 0.1 Hz to 10 MHz revealed increase of six orders magnitude in conductive properties of lignocelluloses fibers coated with polyaniline. Dielectric constant of polyaniline coated lignocelluloses fibers also increased by three to five orders magnitude and revealed weak frequency dependence. Presented morphological and dielectric investigations of directly collected and PANI coated lignocelluloses fibers will open possibilities to develop facile, low-cost, flexible and environment friendly paper substrates for energy storage and disposable electronic applications.

Graphite-based composites are commonly used as an anode and current collector for energy storage devices; however, they have inherently limited potential for large scale rechargeable systems due to a brittle structure. In this study, flexible and light-weight graphite-based electrodes are prepared by incorporation of lignocelluloses fibers directly collected from a self-growing plant, Typha Angistifolia. Electrical properties of graphite and lignocelluloses composite sheets are enhanced by electrodeposition of gold in a three-electrode setup. Electrochemical deposition of gold on a lignocelluloses/graphite paper electrode was obtained in potentiostatic mode by the application of reduction potential −0.95 V for 2000 s, 600 s, and 100 s. The gold-deposited paper electrodes showed efficient kinetics by shifting redox peaks towards lower potentials in cyclic voltammetry measurements, whereas impedance measurements revealed seven orders of magnitude reduction in the resistive properties. Incorporated flexibility and superior electrical/electrochemical performance within presented graphite-based composites will provide cutting-edge characteristics for high-tech application of energy storage devices by keeping a focus on modern disposable technology.

Co-phthalocyanine molecules have wide range of optoelectronics and sensor applications. Motivated by the importance of this material, we studied the adsorption of CoPc thin to thick films on Au(111) surface by using ultraviolet photoelectron spectroscopy (UPS) coupled with angle resolved UPS (AR-UPS) and scanning tunnelling microscopy (STM). Molecular spectral emissions are found to be at 5.13, 7.94, and 10.32 eV below the Fermi level. Observed UPS and AR-UPS measurements show both changes and shifting in valence band features. The work functions of clean Au(111) surface and thick CoPc film are found circa 5.32 eV and 5.25 eV, respectively. Both the work function variation and shifting of molecular features dictate strong adsorbate-substrate interaction. AR-UPS measurements further illustrates that CoPc molecules lie flat on the Au(111) surface. Our STM results disclose that at sub-monolayer (Sub-ML, 0.4–0.8 ML) coverage and room temperature, CoPc molecules tend to adsorb in random fashions; which reveal a strong interaction at the CoPc-Au(111) interface. However, at the ML coverage and elevated temperature (~520K), long range pattern with the oblique structure is observed. Beyond ML coverage, existence of mixed phases consisting of well arranged patterns and molecular clusters have been observed. Overall, our STM results show that depending on the molecular thickness, CoPc molecules form three types of organized oblique, rectangular and square geometries which is consistent with the findings of CuPc and CoPc on Au(111) surface. Our findings may seek potential use in the organic molecular based electronic devices.

Tremendous efforts have been devoted for designing the excellent electrochemical electrode structures, exhibiting good electrochemical characteristics for supercapacitor applications. Herein, nickel sulfide nanoplates on graphene oxide thin film (GO NSNPs) were fabricated on nickel foam using hydrothermal method. The structural, morphological, electrical and electrochemical study was carried out using the X-ray diffractometer, scanning electron microscope, four probe electrical set up and electrochemical work station. GO NSNPs showed oxidation and reduction peaks in cyclic voltammetry curves and recommended the pseudocapacitive nature. The specific capacitance and specific energy was found as 1745.50 Fg−1 and 87.30 WhKg−1 at 5 mAcm−2, respectively, through galvanostatic charge and discharge profile using three electrodes system. While, the measured specific energy from two electrodes symmetric measurements was 15.72 WhKg−1 at 1 mAcm−2. Hence, GO NSNPs electrodes were suggested as suitable for high performance asymmetric and symmetric supercapacitor applications.

The working electrode is considered a major component of the dye-sensitized solar cell (DSSC) to influence the efficiency and morphology attributes in different high-tech applications. This study presents the fabrication of flexible composite sheets of titanium dioxide (TiO2) by incorporation of natural lignocelluloses fibers extracted from the self-growing plant, Typha Angustifolia to address the inherent rigid structure and superior absorption properties of the working electrode. Furthermore, fabricated TiO2 based composites were characterized by scanning electron microscope (SEM), Fourier transforms infrared (FTIR), ultraviolet-visible (UV–vis) spectroscopy and employed as a working electrode for DSSC after deposition on fluorine doped tin oxide (FTO) glass substrate. SEM morphology reveals that LC fibers acted as a thread to bind the TiO2 nanoparticles and also with better voids for adsorption of electrolyte whereas FTIR spectroscopy confirms the successful formation of the paper composite. J-V measurements reveal the high efficiency of 2.95% for TiO2/LC flexible and environmentally safe composite which can be feasible for modern bendable DSSC.

Magnetic heterostructure nanowires with three different compositions (i.e. Au–NiO–Au, Ni–NiO–Ni, and Au–Ni–NiO) were successfully fabricated via simple chronoamperometric technique of the electrochemical deposition. Morphologies and compositions of the prepared samples were analyzed by the field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and x-ray diffraction (XRD), respectively. Magnetic properties of the fabricated nanowires were measured with the help of superconducting quantum interface device (SQUID) in a temperature range (2 ​K–300 ​K). The temperature dependent magnetic properties indicate that the heterostructure nanowires are composed of the superposition of ferromagnetic, anti-ferromagnetic components and exhibiting superparamagnetism and spin-glass like behaviors in different temperature range. Low temperature magnetization reveals high anisotropy of the prepared samples and showing high magnetization at the Ni/NiO interface of the nanowires. These nanostructures might have potential applications in the memory devices.

Various SF6/Ar plasma-textured periodic glass surface morphologies for high transmittance, haze ratio and low sheet resistance of ITO:Zr films are reported. The SF6/Ar plasma-textured glass surface morphologies were changed from low aspect ratio to high aspect ratio with the increase in RF power from 500 to 600 W. The micro- and nano-size features of textured glass surface morphologies enhanced the haze ratio in visible as well as NIR wavelength region. Micro-size textured features also influenced the sheet resistance and electrical characteristics of ITO:Zr films due to step coverage. The ITO:Zr/AZO bilayer was used as front TCO electrode for p-i-n amorphous silicon thin film solar cells with current density–voltage characteristics as: V oc = 875 mV, FF = 70.90 %, J sc = 11.31 mA/cm2, η = 7.02 %.

Reduced size dual band patch antenna is designed on pulp fibers-based substrate, obtained from a self-growing plant, Typha angustifolia. The proposed design is low cost and has

Nanostructured metal oxides have opened innovative and exciting opportunities for exploring intracellular biosensing applications. Metal-oxides-based nanostructures such as zinc oxide/copper oxide (ZnO/CuO) is relatively a biosafe, biocompatible, and large surface area nanostructures with polar surface that can be used for biomedical applications. Metal oxide nanostructures have been widely explored to develop biosensors with high sensitivity, fast response time, and sufficient stability for the determination of intracellular metal ions and glucose by electrochemical methods. In this chapter, we report on a functionalized ZnO-nanostructure-based selective electrochemical sensor for intracellular metal ions and glucose. To apply the biosensor concept to intracellular and less invasive measurements based on nanostructured metal oxides, hexagonal ZnO nanorods were grown on the tip of a silver-covered borosilicate glass capillary (0.7 µm diameter) and coated with the membrane/enzyme. The membrane/enzyme-coated ZnO nanorods exhibited a metal ions/glucose-dependent electrochemical potential difference versus an Ag/AgCl reference microelectrode. The potential difference was linear over a wide concentration range of interest. The effect of the hormone insulin and extracellular injected metal ions, which increased the concentration of intracellular glucose/metal ions, was also demonstrated. These results demonstrate the capability to perform biologically relevant measurements of metal ions/glucose within living cells. The ZnO nanorod metal ions/glucose electrode thus holds promise for minimally invasive dynamic analyses of single cells. The measured metal ions/glucose concentration in human adipocytes or frog oocytes using ZnO nanorod sensor was consistent with values reported in the literature. This microelectrode device represents a simple but powerful technique to measure intracellular metal ions/glucose concentration which is of particular importance with regard to investigations into bone destruction/diabetes and its consequences.

This paper reported an electrochemical potentiometric glucose biosensor, developed by immobilizing glucose oxidase on an electrode consisting of Au/Ni/Au nanowires. Electrochemically deposited nanowires are bridged between two gold electrodes. Field emission scanning electron microscope (FESEM) and energy-dispersive x-ray spectroscopy (EDS) are used for the morphological characterization of nanostructures. The device is tested by electrochemical potentiometric and simple IV measurement techniques. In order to check the glucose potentiometric response, nanowires are coated with enzyme, glucose oxidase which revealed a glucose dependant electrochemical response versus reference electrode (Ag/AgCl). Electrochemical response of the sensor is found to be linear in range of 0.5?10 mM. Fabrication of Au/Ni/Au nanowires by facile method will provide the opportunity for glucose biosensors to measure glucose by simple and direct technique.

In era of modern disposable and bendable energy storage technology, flexible and environmentally safe electrodes are extremely feasible. This study elaborates the synthesis of highly flexible and stretchable polymer gel membrane by covalently cross linking of chitosan (CS) and poly vinyl alcohol (PVA) immobilized MnO2 for efficient, light-weight and cost-effective energy storage technologies. Fourier transform infrared spectroscopy (FTIR) revealed the existence of CS/PVA as well as MnO2 in original form without any chemical change. 3-dimensional morphology including porosity of the presented fabricated membranes are examined by scanning electron microscopy (SEM). Presented CS/PVA based MnO2 membranes were bendable and can be cut in any shape by the simple usage of scissor to employ by means of working electrode. Furthermore, electrochemical behaviour was tested by cyclic voltammetry (CV) and Galvanostatic charge/discharge (GCD) measurements in neutral/acidic electrolytes. CS/PVA based MnO2 membranes showed excellent capacitive behaviour with specific capacitance of ~140 F g−1. GCD measurements also verified efficient kinetics of charging/discharging at low and high current rates as curves were symmetric. Presented flexible and electroactive CS/PVA based MnO2 membranes will be highly suitable candidates for bendable electrode material in modern high-tech flexible energy storage devices.