This article reports facile fabrication of a multifunctional smart surface having superhydrophobic self-cleaning property, superoleophilicity, and antimicrobial property. These smart surfaces have been synthesized using the stereolithography (SLA) method of the additive manufacturing technique. SLA is a fast additive manufacturing technique used to create complex parts with intricate geometries. A wide variety of materials and high-resolution techniques can be utilized to create functional parts such as superhydrophobic surfaces. Various materials have been studied to improve the functionality of 3D printing. However, the fabrication of such materials is not easy, as it is quite expensive. In this work, we used a commercially available SLA printer and its photopolymer resin to create various micropatterned surfaces. Additionally, we applied a low surface energy coating with ZnO nanoparticles and tetraethyl orthosilicate to create hierarchical roughness. The wettability studies of created superhydrophobic surfaces were evaluated by means of static contact angle using the sessile drop method and rolling angle measurements. The effects of various factors, including different concentrations of coating mixture, drying temperatures, patterns (pyramids, pillars, and eggbeater structures), and pillar spacing, were studied in relation to contact angles. Subsequently, all the functional properties (i.e., self-cleaning, oleophilicity, and antibacterial properties) of the as-obtained surfaces were demonstrated using data, images, and supporting videos. This inexpensive and scalable process can be easily replicated with an SLA 3D printer and photopolymer resin for many applications such as self-cleaning, oil–water separation, channel-less microfluidics, antibacterial coating, etc

Gold nanoclusters (Au NCs) have found wide range of applications in environmental, chemical and health sectors as sensors, catalytic agents and theranostic molecules, respectively, due to their ultrasmall size and excellent optical properties. However, a comprehensive battery of bioassays of Au NCs were lacking on a well-established biological model system, which would enhance its potential to be used as an optical probe with application in theranostics. The current investigation aims to address the in vivo compatibility of Au NCs to improve their design, evaluate their biological impact, and validate their potential for bioimaging applications. We have used the Caenorhabditis elegans as a model organism in our present study due to their short life cycle facilitating evaluation of drug effects in reasonable time frame and transparent body framework suitable for in vivo imaging. These features facilitate accurate information regarding the uptake and biodistribution of Au NCs inside the tissues and body parts. Additionally, different nanotoxicological studies such as biodistribution of NCs and its subsequent impact on the health span, brood size, pharyngeal pumping and tail thrashing of C. elegans were observed as a measure of the Au NCs biocompatibility. Our results strongly demonstrate that the human serum albumin (HSA)-bound Au NCs are non-toxic, biocompatible and do not exhibit any adverse effect on the physiology and survival of the C. elegans. This study, employing a comprehensive battery of bioassays, is the first to systematically evaluate the long-term biocompatibility and non-toxicity of Au NCs across the entire lifespan of an organism, measured through multiple physiological parameters. These findings underscore the potential of Au NCs as safe and effective diagnostic and therapeutic agents for medical and clinical applications

Renewable energy has gained widespread recognition for its potential to drive sustainable power generation and mitigate climate change. However, the rapid expansion of these resources highlights inherent challenges arising from their non?dispatchable, intermittent, and asynchronous nature, underscoring the critical need for grid?scale energy storage. Although numerous storage technologies exist, cohesive insights into commercially available or nearing commercialization remain limited. The review addresses that gap by presenting a comprehensive analysis of marketable grid?scale energy?storage solutions. The discussion begins with an examination of growth dynamics and regional trends in energy?storage capacities worldwide. By using California and Saudi Arabia as representative samples of the Mediterranean and hot desert regions under the Köppen classification, the review illustrates how climatic zones influence energy?storage requirements. After highlighting recyclability challenges associated with lithium?ion batteries, the study explores emerging electrochemical and gravitational?storage technologies. It then articulates critical parameters for evaluating energy?storage solutions and provides a comparative performance analysis. The review concludes by identifying a range of commercialized innovations and recommending a holistic approach to strengthen reliance on renewable energy

Reduced graphene oxide (rGO) has captivated the scientific community due to its exceptional electrical conductivity, high specific surface area, and excellent mechanical strength. The physical properties of reduced graphene oxide (rGO) are strongly dependent on the presence of different functional groups in its structural framework, along with surface roughness. In this study, laser annealing was employed by a nanosecond Nd:YAG laser to investigate the impact of varying laser energies on the wettability and conductivity of reduced graphene oxide (rGO) samples grown by the pulsed laser deposition (PLD) technique. The rGO films were annealed with different laser fluences, such as 10, 20, 30, 38, 48, 55, and 250 mJ/cm2. Our results reveal a notable transition in wettability, transforming the initially hydrophobic rGO samples into a hydrophilic state. Hydrophilic graphene oxide (GO) or reduced graphene oxide (rGO) surfaces have significant potential for use in biomedical applications due to their unique combination of properties, including biocompatibility, high surface area, and abundant oxygen-containing functional groups. Along with wettability properties, conductivity changes were also observed. The presented findings not only contribute to the understanding of laser-induced modifications in rGO but also highlight the potential applications of controlled laser annealing in tailoring the surface properties of graphene-based materials for diverse technological advancements

Highly crystalline hematite (?-Fe2O3) nanostructures (NSs) with distinct morphology hold vital significance, not only for fundamental knowledge of magnetic properties but also offering potential applications from biomedical to data storage to semiconductor industry, etc. ?-Fe2O3 NSs with various shapes are examined to reveal the intrinsic relationship between the shape anisotropy and magnetic properties. Herein, different morphologies of ?-Fe2O3 NSs, such as spherical, cubic, plate-like, rhombohedral, and hexagonal bipyramid are synthesized, by controlled hydrothermal method. The impact of shape and size on the optical and structural characteristics through UV–vis absorption spectroscopy and X-ray diffraction is analyzed. Advanced nanomaterial techniques such as transmission electron microscopy are utilized to explore and confirm the morphology and size of NSs. Subsequently magnetic properties of the ?-Fe2O3 NSs, such as magnetic saturation (Ms), coercivity (Hc), and remanent magnetization (Mr), are measured. Careful analysis of magnetic data reveals Morin transition around 200K for cubic, plate-like, and rhombohedral samples, whereas the spherical and hexagonal bipyramid samples illustrate the superparamagnetic behavior in the temperature range of 150–300K. Finally, the antibacterial characteristics of NSs against Escherichia coli using a microplate reader for monitoring the bacterial growth are investigated

The authors regret the oversight in one of the author's (Manjunatha Thondamal) affiliation details occurred during the final proof reading. The affiliation detail for the author- Manjunatha Thondamal is: d Department of Biotechnology, School of Technology, Gandhi Institute of Technology and Management (GITAM), Visakhapatnam, Andhra Pradesh, 530045, India. The authors would like to apologise for any inconvenience caused.

The recent year has witnessed a flurry of activities in investigating the promising electronic, optical, and transport properties of lead-free double perovskite halides. In the present work, the structural, electronic, optical, and transport properties of Cs2(Li/Na)GaI6 are carefully examined. The predicted negative formation energy, absence of imaginary frequency in the phonon spectra, and ab-initio molecular dynamics calculations show that they are thermodynamically stable. Additionally, electronic studies employing generalized gradient approximation (GGA)–Perdew–Burke–Ernzerhof (PBE) + modified Becke-Johnson + spin-orbit coupling reveal that Cs2(Li/Na)GaI6 exhibits a direct bandgap, with values of 1.24 eV for Cs2LiGaI6 and 1.39 eV for Cs2NaGaI6. The exceptional optical properties, including a high absorption coefficient (105 cm?1) and excellent optical conductivity with low reflectivity across the entire UV–visible range, indicate that Cs2(Li/Na)GaI6 are promising materials for solar cell applications. Moreover, the ultralow thermal conductivity, high Seebeck coefficient, and substantial electrical conductivity of Cs2(Li/Na)GaI6 result in a high figure of merit over the temperature range of 200–600 K. Thus, Cs2(Li/Na)GaI6 shows strong potential as both photovoltaic and thermoelectric materials. © 2024 Wiley-VCH GmbH.

Hydrogen is emerging as a strong contender for a feasible future energy carrier in the clean energy race, due to its high energy density and clean burning nature. However, to account for the environmental and energy challenges, its production must be sustainable and cost-efficient. Currently, hydrogen is generated from various feedstocks such as ammonia, methane, natural gas, biomass, smaller organic molecules, and water. These feedstocks undergo different catalytic processes, including catalytic decomposition, electrolysis, steam reforming, pyrolysis, gasification, and photoassisted methods such as photoelectrochemical, biophotolysis, and photocatalysis, etc. Among all, the research on water electrolysis has garnered much attention because of their carbon free green hydrogen production with the use of water electrolyzers (WEs). On the basis of recent reports from the International Renewable Energy Agency (IREA), the major types of water electrolyzers used in the industry are alkaline water electrolyzers (AWE), proton-exchange membrane water electrolyzers (PEMWEs), and anion-exchange membrane water electrolyzer (AEMWE). Among them, AWEs and PEMWEs have their inherent drawbacks which need attention. AEMWEs can be considered as a promising alternative by integrating the advantages of both AWEs and PEMWEs into one device. In this review, we have focused on the core ideas of AEMWEs, where the recent scientific and engineering breakthroughs are highlighted. It points out the importance of eliminating the gap between electrodes (i.e., zero gap concept) and identifies areas that need further development to push AEMWE technology forward. AEMWEs offer advantages such as higher operating current densities and pressures, comparable Faradaic efficiencies (>90%), and the utilization of nonprecious metal catalysts along with pure water feed. Along with all these, we have also focused on the advancements and deterioration of AEMs. Additionally, it provides a concise overview of AEMWE membrane performance and offers a detailed examination of developments in electrolyte feeding and the utilization of nonprecious group metal (non-PGM) electrocatalysts. © 2024 American Chemical Society.

Neuromorphic devices with extremely low energy consumption are greatly demanded for brain-like computing and artificial intelligence (AI). In this work, the ZnO–NiO nanocomposite as an active layer used to create artificial synaptic memristor devices with memory functions, including high ON/OFF ratios, stable and filamentary resistive switching behavior, long-term/short-term plasticity (LTP/STP), and learning-experience response. These qualities closely resemble biological learning and memory activities. Controlled production and rupture of Ag filaments result in resistive switching with a switching ratio of ?103, making them ideal for nonvolatile memory demands. Before electroforming, the progressive conductance modulation of a Ag/ZnO/NiO/Pt/Ti/SiO2 memristor may be observed, and the working mechanism described by the subsequent development and contraction of Ag filaments induced by a redox reaction. Furthermore, the nanocomposite memristors demonstrated an exponential decay curve with a 2.26 ?s decay time constant and an artificial neural network (ANN) with outstanding identification accuracy of 90.7% for handwritten digits. This work suggests that the proposed memristors (with a stable and mutifuntional responses) might enable efficient neuromorphic designs

Novel dielectrics with electrostatic energy storage capabilities attracted significant attention in recent years for high-energy storage applications due to their high-power density. The structural, electrical, and dielectric properties play a pivotal role in attaining high power densities in dielectric ceramics. Here, the authors presented the influence of CaTiO3 on the structural, electrical, and dielectric properties of BiFeO3-CaTiO3 (BFO-CTO) lead-free ceramics. (BFO)(1?x)–(CTO)x (x=0, 0.1, 0.3, and 0.5 and 1) ceramics were fabricated from calcined powders of BFO and CTO using the microwave sintering technique. Due to the partial substitution of Ca2+ and Ti4+ into the A and B sites (of Bi3+ and Fe3+, respectively) structural phase transformation occurred from rhombohedral to orthorhombic crystal structure for x?0.3. As the CTO concentration is increased, the resistivity of BFO-CTO samples is enhanced by two orders of magnitude, from 2.21×103 ? cm (x=0) to 8.80×105 ? cm (x=0.5). The leakage current density was reduced by two orders of magnitude, from~2.60×10–1 A cm?2 (x=0) to~2.50×10–3 A cm?2 (x=0.5). The improved resistivity, reduced leakage current and enhanced dielectric properties make lead-free BFO-CTO dielectrics as an excellent alternative to existing energy storage systems.

Self-cleaning surfaces revolutionizing the technology world due to their novel property of cleaning themselves, and its multi-functional self-cleaning surfaces exhibit at least one or more functional properties (transparent, conducting, anti-bacterial, anti-corrosion, etc.) This review article focuses on the fundamentals of wettability, material parameters controlling surface wettability and three different paths to realization of self-cleaning surfaces, i.e., (i) super-hydrophobic, (ii) super-hydrophilic and (iii) photocatalytic. The subsequent part of the article mostly focuses on the super-hydrophobic path towards realizing self-cleaning surfaces. In the super-hydrophobic path, the objective is to make the surface extremely repellent to water so that water droplets slide and ‘roll off’ from the surface. The next section of the review article focuses on the role of additive manufacturing in the fabrication of super-hydrophobic micro-structures. Amidst the different fabrication processes of self-cleaning surfaces, additive manufacturing stays ahead as it has the manufacturing capacity to create complex micro-structures in a scalable and cost-effective manner. A few prominent types of additive manufacturing processes were strategically chosen which are based on powder bed fusion, vat photopolymerization, material extrusion and material jetting techniques. All these additive manufacturing techniques have been extensively reviewed, and the relative advantages and challenges faced by each during the scalable and affordable fabrication of super-hydrophobic self-cleaning surfaces have been discussed. The article concludes with the latest developments in this field of research and future potential. These surfaces are key to answer sustainable development goals in manufacturing industries. Graphical abstract: (Figure presented.) © The Author(s) 2024.

The ceria-tin/alumina mixed metal oxides (Ce/Sn =1) with different proportions of Fe & Mn dopants were synthesized and investigated in detailed approach for diesel emission reduction. The dopants created structural defects enhancing the oxygen ion mobility for exhaust treatment. The existence of surface-active oxygen sites and oxygen ion vacancy sites generated for charge compensation due to reduction of Ce4+, Sn4+ and dopants incorporation evidenced from XPS analysis. The Mn doped sample holds better physicochemical properties than Fe doped sample. The Mn doped sample with higher surface area of about 101.32 m2 g?1 exhibits greater active sites for better catalytic activity. The redox couples in the Mn-doped sample Ce4+/Ce3+, Sn4+/Sn2+, and Mn3+/Mn2+ helps in oxygen regeneration to contribute to exhaust treatment by oxygen ion conduction from bulk to the surface. This sample exhibited the 92 % of NOx reduction and proved to be a dynamic candidate for diesel emission reduction. © 2024 Elsevier Ltd

This research article focuses on analyzing the behavior of high-temperature dielectric relaxation and electric conduction mechanisms in Bi1-xNdxFeO3 (BNFO) samples, where the value of x varies as 0, 0.10, 0.15, and 0.2. The study’s findings indicate that all these samples exhibit two distinct dielectric transitions. The first transition occurs at a lower temperature (Ts), typically in the range of 425 to 450 K, and is characterized by a frequency-dependent shoulder. This transition is associated with the presence of polar nanoregions (PNRs). The second transition takes place within a temperature range of approximately 580 to 650 K, marking the transition from a ferroelectric to a paraelectric state at the Curie temperature (TC). Furthermore, impedance analysis of the specimens reveals a negative temperature coefficient of resistance, indicating a wide range of relaxation behavior that does not conform to the Debye-type model. Additionally, the study of conductivity provides valuable insights into the transport phenomena observed in these samples. The obtained energy storage properties of these bulk ceramics are quite significant compared to the similar systems reported in the literature. © 2024 American Chemical Society.

The increasing global demand for energy solutions has created the necessity for innovative nanocomposite materials for efficient energy storage applications. This urgency is driving significant advancements in energy storage technologies, raising hope for the future of energy sectors. Supercapacitors (SCs), high-performance electrochemical storage devices, have earned considerable attention to address these challenges. In this article, we have demonstrated a cost-effective, easily obtainable trimetallic spinel/defect-spinel oxide ZnMnO/CuMnO (ZMO/CMO) nanocomposite through a facile one-step solvothermal synthesis process. This nanocomposite demonstrated exceptional charge storage capabilities. The charge storage mechanism was established by using Dunn’s method, which reveals the diffusive nature of the electrode material. The ZMO/CMO nanocomposite exhibits an impressive specific capacitance of 468.1 F/g at 0.5 A/g, with 84% capacity retention even after 20000 cycles, which was attributed to the oxygen vacancies within the defect spinel structure. Moreover, we fabricated an asymmetric device utilizing ZMO/CMO as the cathode and activated carbon (AC) as the anode. This device attained an energy density of 48.1Wh/kg and a power density of 700 W/kg with excellent cycling stability, as mentioned before. Furthermore, our study featured its ability to power a standard LED light.

This paper presents a comprehensive overview of the potential applications for Photo-Acoustic (PA) imaging employing functional nanoparticles. The exploration begins with an introduction to nanotechnology and nanomaterials, highlighting the advancements in these fields and their crucial role in shaping the future. A detailed discussion of the various types of nanomaterials and their functional properties sets the stage for a thorough examination of the fundamentals of the PA effect. This includes a thorough chronological review of advancements, experimental methodologies, and the intricacies of the source and detection of PA signals. The utilization of amplitude and frequency modulation, design of PA cells, pressure sensor-based signal detection, and quantification methods are explored in-depth, along with additional mechanisms induced by PA signals. The paper then delves into the versatile applications of photoacoustic imaging facilitated by functional nanomaterials. It investigates the influence of nanomaterial shape, size variation, and the role of composition, alloys, and hybrid materials in harnessing the potential of PA imaging. The paper culminates with an insightful discussion on the future scope of this field, focusing specifically on the potential applications of photoacoustic (PA) effect in the domain of biomedical imaging and nanomedicine. Finally, by providing the comprehensive overview, the current work provides a valuable resource underscoring the transformative potential of PA imaging technique in biomedical research and clinical practice.

The development of high-performance electrostatic energy storage dielectrics is essential for various applications such as pulsed-power technologies, electric vehicles (EVs), electronic devices, and the high-temperature aviation sector. However, the usage of lead as a crucial component in conventional high-performance dielectric materials has raised severe environmental concerns. As a result of this, there is an urgent need to explore lead-free alternatives. Ferroelectric ceramics offer high energy density but lack stability at high temperatures. Here we present a lead-free (1 - x)BiFeO-xCaTiO (x = 0.6, 0.7, and 0.8; BFO-CTO) ceramic capacitor with low dielectric loss, high thermal stability, and high energy density up to ?200 °C. The introduction of CTO (x = 0.7) to the BFO matrix triggers a transition from the normal ferroelectrics to the relaxor ferroelectrics state, resulting in a high recoverable energy density of 1.18 J cm at 190 °C with an ultrafast dielectric relaxation time of 44 ?s. These results offer a promising, environmentally friendly, high-capacity ceramic capacitor material for high-frequency and high-temperature applications.

High-quality copper oxide (CuO) thin films were deposited on the silicon (Si) substrate at the room temperature using the physical vapour deposition (PVD) technique named radio frequency (RF) sputtering. The copper-oxide thin-films were single crystalline and of uniform thickness. Subsequently, the influence of growth pressure (low gas pressure - 3 mTorr and high gas pressure - 100 mTorr) and post growth annealing at different temperatures (300 °C to 700 °C) were investigated to understand the microstructural and morphological changes of the thin film. With the influence of growth pressure and post thermal annealing temperature, significant changes in crystallinity, surface roughness, and surface oxidation rate of the CuO thin film were detected, which were adequately analyzed via several characterization techniques. X-ray diffraction (XRD) patterns revealed the phase formation with good crystallinity of the film, which is substantiated by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) characterization. Atomic force microscopy (AFM) images disclosed that the surface roughness of the film and grain size. By gaining insights into the structural and surface properties of CuO/Si thin films, this research presents new prospects for tuning of CuO phases, structures, and compositions for multifunctional applications.

Photovoltaic systems (PV), particularly solar photovoltaics, are gaining popularity as renewable energy sources. The rapid deployment of PV systems has attracted substantial investments, with around $170 billion projected by 2025. However, challenges like dust accumulation, solar radiation, and temperature rise hinder PV efficiency. Elevated temperatures, exceeding standard levels, notably decrease voltage output and overall electricity generation efficiency. This review provides a comprehensive overview of recent cooling techniques adopted to enhance solar PV performance. Beginning with an introduction to global warming's impact and renewable energy's significance, the article explores cooling methodologies for solar PVs. These encompass Absorption & adsorption-based, PV/T hybrid, Microtechnology-based, and Water and air-based cooling systems. The review concludes this section with a detailed table comparing cooling technologies' performance, benefits, and challenges. The review then delves into four primary cooling techniques: Active cooling, Passive cooling, Nanofluid-based cooling, and Thermoelectric cooling. Passive cooling, which effectively reduces PV system temperature without external energy sources, is highlighted. Modalities of Passive cooling methods, such as Radiative cooling, Evaporative cooling, Liquid immersions, and Material coatings, are elaborated. Concluding, the article addresses challenges, opportunities, and future prospects related to diverse cooling techniques' utilisation, aiming to elevate solar PV system efficiency.

This review article focuses on the role of nanotechnology (NT) in the development of advanced organic and inorganic photodetectors and their potential applications in the coming decades. We initiate the article with an overview of NT and potential applications of Nanotechnology in the twenty-first century ranging from Semiconductor manufacturing to Medical Imaging to Renewable energy to Quantum computing to Opto-electronics. The second part of the article delved into specific details on the role of nanotechnology and nanomaterials in developing advanced Photodetectors (PDs) and specifically discussing the internal functioning of near-infrared (NIR) photodetectors. Subsequently we focused on the performance metrics of PDs and types of PDs namely Organic Photodetectors (OPD) and Inorganic Photodetectors (IPD). We continued our in-depth discussion on OPDs and IPDs elaborating their structural features, operation mechanisms, types, performance optimization and role of functional nanomaterials. The final part of this review focuses on key applications of photodetectors e.g., retinal implant, biomedical imaging, personalized health monitoring, telecommunication, and military applications etc. Finally, we concluded the review paper discussing future opportunities and challenges regarding applications of NIR photodetectors in the twenty-first century. Graphical Abstract: [Figure : see fulltext.]

The Southeast Asian (SEA) region has witnessed a relentless surge in energy demand, driven by rapid urbanization, industrialization, and economic growth. In response, the exploration and development of renewable energy sources have gained significant attention. Among these sources, solar energy has emerged as a highly promising candidate due to its remarkable growth rate. This comprehensive review article aims to analyze the challenges and opportunities involved in maximizing solar energy production in the SEA region. The article commences with a succinct introduction to electromagnetic wave spectra and emphasizes the significance of visible spectra. It then provides a comprehensive examination of gross horizontal irradiance (GHI) patterns across the SEA region. A systematic tabulation is presented, organizing the current and potential solar energy installations and outputs of ASEAN countries. The article explores the deployment of hybrid photovoltaic (PV) systems, particularly floating PV installations, as an effective strategy to reduce dependence on fossil fuels. Moreover, the utilization of Supervisory Control and Data Acquisition (SCADA) systems for optimizing solar PV output is investigated. The article further delves into critical maintenance protocols, encompassing corrective, emergency, preventive, and predictive measures, and explores the levelized cost of electricity (LCOE) to assess the profitability of solar PV installations. Lastly, the leadership of Malaysia, Indonesia, and Singapore in solar PV research is highlighted, with a specific focus on building integrated PV and floating PV research. By addressing these, this review article offers valuable insights into the challenges and opportunities for advancing solar energy production in the SEA region.

The electrode material properties, such as widening the voltage window, rational design, and morphology are known to play an essential role in increasing its efficiency for energy storage devices. Herein, a simple strategy to first prepare a Mg(OH)/Cu(OH)(NO) (MHCN) binary heterostructure by co-precipitation method. The morphology studies from SEM and HR-TEM analysis revealed that the Mg(OH) and Mg(OH)/Cu(OH)(NO) binary heterostructures show quasi-spherical and nanosheet-like structures. The electrochemical characteristics of as-prepared binary heterostructure electrodes were investigated by a three-electrode system. At a low current density of 5 Ag, the specific capacitance of the MHCN-2 achieved 146 Fg. The MHCN-2 electrode displayed capacitance retention of ~ 97% and coulombic efficiency of ~ 96% for 5000 cycles. This study offers a facile and low cost approach for producing novel nanostructures and electrodes for energy storage in binary heterostructure materials. Graphical Abstract: [Figure : see fulltext.].

A novel memory capacitor structure has been presented with AlO/AlO bilayer dielectrics on high mobility Epitaxial-GaAs substrate. We have demonstrated the chemical and electrical properties of metal–electrode/AlO/AlO/epi-GaAs-based memory device in detail. Sputter-grown non-stoichiometric AlO has been used for both the charge trapping layer and blocking layer due to its intrinsic charge trapping capability and high bandgap. Ultra-thin tunneling layer of thicknesses 5 nm and 15 nm were prepared by atomic layer deposition technique and memory properties were compared on promising high mobility Epitaxial-GaAs/Ge heterostructure. The proposed device shows excellent charge trapping properties with a maximum memory window of 3.2 V at sweep voltage of ± 5 V, with good endurance and data retention properties. Oxygen-deficient AlO layer acted as a charge trapping layer without any additional blocking layer which is impressive for non-volatile memory application on high mobility epi-GaAs substrate. In addition, density Functional Theory (DFT) has been employed to understand the physical origin of the intrinsic charge trapping defects in AlO dielectric layer.

Morphological changes of copper oxide (CuO) nano-structures have been studied in detail for renewable energy and electronic applications. The CuO nano-structures were grown on a silicon substrate via a two-stage process starting with radio frequency sputtering for the seed layer followed by chemical bath deposition. The study was focused on controlling the shape and size of the CuO nano-structures depending on various growth conditions, such as reaction time, growth temperature, and vertical/horizontal orientation of the substrate containing the sputtered-grown seed layer. Structural, optical, crystallographic, and morphological characteristics of the nano-structures were obtained through field-emission scanning electron microscopy, x-ray diffraction crystallographic analysis, and UV–Vis spectroscopy.

Antiferromagnetic insulators are a ubiquitous class of magnetic materials, holding the promise of low-dissipation spin-based computing devices that can display ultra-fast switching and are robust against stray fields. However, their imperviousness to magnetic fields also makes them difficult to control in a reversible and scalable manner. Here we demonstrate a novel proof-of-principle ionic approach to control the spin reorientation (Morin) transition reversibly in the common antiferromagnetic insulator ?-FeO (haematite) – now an emerging spintronic material that hosts topological antiferromagnetic spin-textures and long magnon-diffusion lengths. We use a low-temperature catalytic-spillover process involving the post-growth incorporation or removal of hydrogen from ?-FeO thin films. Hydrogenation drives pronounced changes in its magnetic anisotropy, Néel vector orientation and canted magnetism via electron injection and local distortions. We explain these effects with a detailed magnetic anisotropy model and first-principles calculations. Tailoring our work for future applications, we demonstrate reversible control of the room-temperature spin-state by doping/expelling hydrogen in Rh-substituted ?-FeO.

Cupric oxide (CuO) is a promising candidate as a photocathode for visible-light-driven photo-electrochemical (PEC) water splitting. However, the stability of the CuO photocathode against photo-corrosion is crucial for developing CuO-based PEC cells. This study demonstrates a stable and efficient photocathode through the introduction of graphene into CuO film (CuO:G). The CuO:G composite electrodes are prepared using graphene-incorporated CuO sol–gel solution via spin-coating techniques. The graphene is modified with two different types of functional groups, such as amine (-NH) and carboxylic acid (-COOH). The -COOH-functionalized graphene incorporation into CuO photocathode exhibits better stability and also improves the photocurrent generation compare to control CuO electrode. In addition, -COOH-functionalized graphene reduces the conversion of CuO phase into cuprous oxide (CuO) during photo-electrochemical reaction due to effective charge transfer and leads to a more stable photocathode. The reduction of CuO to CuO phase is significantly lesser in CuO:G-COOH as compared to CuO and CuO:G-NH photocathodes. The photocatalytic degradation of methylene blue (MB) by CuO, CuO:G-NH and CuO:G-COOH is also investigated. By integrating CuO:G-COOH photocathode with a sol–gel-deposited TiO protecting layer and Au–Pd nanostructure, stable and efficient photocathode are developed for solar hydrogen generation.

Reduced graphene oxide (rGO) has attracted significant interest in an array of applications ranging from flexible optoelectronics, energy storage, sensing, and very recently as membranes for water purification. Many of these applications require a reproducible, scalable process for the growth of large-area films of high optical and electronic quality. In this work, we report a one-step scalable method for the growth of reduced-graphene-oxide-like (rGO-like) thin films via pulsed laser deposition (PLD) of sp carbon in an oxidizing environment. By deploying an appropriate laser beam scanning technique, we are able to deposit wafer-scale uniform rGO-like thin films with ultrasmooth surfaces (roughness <1 nm). Further, in situ control of the growth environment during the PLD process allows us to tailor its hybrid sp-sp electronic structure. This enables us to control its intrinsic optoelectronic properties and helps us achieve some of the lowest extinction coefficients and refractive index values (0.358 and 1.715, respectively, at 2.236 eV) as compared to chemically grown rGO films. Additionally, the transparency and conductivity metrics of our PLD grown thin films are superior to other p-type rGO films and conducting oxides. Unlike chemical methods, our growth technique is devoid of catalysts and is carried out at lower process temperatures. This would enable the integration of these thin films with a wide range of material heterostructures via direct growth.

This chapter discusses about recent advancements on smart coating and their potential applications in smart window engineering. First part of this book-chapter will discuss about recent developments in Smart-window technology. It has potential to exhibit different applications using various sources such as light, heat, and voltage to produce unique properties. In comparison to normal static windows, smart windows can modulate solar transmittance of NIR and visible light depending on weather conditions and personal preferences of human beings inside the door. Although very few smart windows are commercially available in the market, their demand is not yet to be realized. On the other hand, latest engineered nanostructured materials contribute new opportunities for future smart window technology. Initially, this article will elaborate the antibacterial activities of smart coating technology. Antibacterial surfaces are of great importance due to their potential application in coating of medical devices and implants, paints, food packaging, transportation etc. Final section of this chapter will illustrate wettability research done on novel material surfaces including smart windows. Understanding solid–liquid interface at fundamental level is of tremendous implication due to their potential application in creating self-cleaning and self-lubricating surfaces. These types of advanced thin film surfaces can have multiple potential applications ranging from everyday life to advanced technological utilization such as transparent coating of smart windows to microfluidics to fabrication of advanced nano-biomaterials.

This paper presents a new dynamic reactive power estimation based transient voltage control for grid integrated DFIG by coordinating Rotor Side Controller (RSC), Grid side Controller (GSC) and pitch control. During transient grid voltage changes, the proposed architecture calculates a reference reactive and active power using the designed adaptive controller and P-V droop controller with the machine operating limits into consideration while ensuring the maximum reactive power support is achieved. This is crucial to the stability of both the machine and the power grid. Based on this, the existing machine and pitch controllers are coordinated. The test results with professional grade nonlinear simulator considering practical GE 1.5MW system parameters show that, when compared to the existing Doubly Fed Induction Generator (DFIG) control methodologies, the approach provides at an average 20-30% improvement in voltage restoration and ensures maximum reactive power support without violating machine limits.