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Ultrathin (1–4 nm) films of wide-bandgap semiconductors are important to many applications in microelectronics, and the film properties can be sensitively affected by defects especially at the substrate/film interface. Motivated by this, an in vacuo atomic layer deposition (ALD) was developed for the synthesis of ultrathin films of Ga2O3/Al2O3 atomic layer stacks (ALSs) on Al electrodes. It is found that the Ga2O3/Al2O3 ALS can form an interface with the Al electrode with negligible interfacial defects under the optimal ALD condition whether the starting atomic layer is Ga2O3 or Al2O3. Such an interface is the key to achieving an optimal and tunable electronic structure and dielectric properties in Ga2O3/Al2O3 ALS ultrathin films. In situ scanning tunneling spectroscopy confirms that the electronic structure of Ga2O3/Al2O3 ALS can have tunable bandgaps (Eg) between ∼2.0 eV for 100% Ga2O3 and ∼3.4 eV for 100% Al2O3. With variable ratios of Ga:Al, the measured Eg exhibits significant non-linearity, agreeing with the density functional theory simulation, and tunable carrier concentration. Furthermore, the dielectric constant ε of ultrathin Ga2O3/Al2O3 ALS capacitors is tunable through the variation in the ratio of the constituent Ga2O3 and Al2O3 atomic layer numbers from 9.83 for 100% Ga2O3 to 8.28 for 100% Al2O3. The high ɛ leads to excellent effective oxide thickness ∼1.7–2.1 nm for the ultrathin Ga2O3/Al2O3 ALS, which is comparable to that of high-K dielectric materials. [ABSTRACT FROM AUTHOR]

Due to its excellent insulativity, thermal conductivity, chemical inertness and ultraflat surface, multilayer hexagonal boron nitride (h-BN) has become a favorable dielectric for two-dimensional materials or other conventional semiconductors. Multilayer h-BN can also serve as a functional material in deep ultraviolet optoelectronic or novel memory devices. However, the utilization of h-BN in electronic and optoelectronic applications has been severely impeded by the challenge of preparing large-area multilayer thin films. In this work, we achieved the controlled synthesis of centimeter-scale multilayer h-BN using a space confined route within an atmospheric pressure chemical vapor deposition (APCVD) system. Using thorough material characterization, the uniformity of multilayer h-BN is identified. We find that the thickness of multilayer h-BN can be fine-tuned with APCVD parameters and the growth mechanism in the confined space is systematically scrutinized. The multilayer h-BN thin film is further used as the gate dielectric for a hydrogen-terminated diamond field effect transistor (FET), which exhibits comparable performance with the devices with common dielectrics. Our work provides a novel strategy for the large-scale synthesis of multilayer h-BN thin films, paving the way for realizing its full potential in a panoply of applications. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) materials have been identified as promising candidates for future electronic devices. However, high dielectric constant (κ) materials, which can be integrated with 2D semiconductors, are still rare. Here, we report a hydrate-assisted thinning chemical vapor deposition (CVD) technique to grow manganese oxide (Mn3O4) single crystal nanosheets, enabled by a strategy to minimize the substrate lattice mismatch and control the growth kinetics. The material demonstrated a dielectric constant up to 135, an equivalent oxide thickness (EOT) as low as 0.8 nm, and a breakdown field strength (Ebd) exceeding 10 MV/cm. MoS2 field-effect transistors (FETs) integrated with Mn3O4 thin films through mechanical stacking method operate under low voltages (<1 V), achieving a near 108 Ion/Ioff ratio and a subthreshold swing (SS) as low as 84 mV/dec. The MoS2 FET exhibit nearly zero hysteresis (<2 mV/MV cm⁻¹) and a low drain-induced barrier lowering (~20 mV/V). This work further expands the family of 2D high-κ dielectric materials and provides a feasible exploration for the epitaxial growth of single-crystal thin films of non-layered materials. High dielectric constant (κ) materials compatible with van der Waals materials are desired to promote the development of 2D electronics. Here, the authors report a method to grow Mn3O4 nanosheets exhibiting κ up to 135 and equivalent oxide thickness down to 0.8 nm, enabling the fabrication of high-performance 2D MoS2 transistors. [ABSTRACT FROM AUTHOR]

As the feature size of microelectronic circuits is scaling down to nanometer order, the increasing interconnect crosstalk, resistance-capacitance (RC) delay and power consumption can limit the chip performance and reliability. To address these challenges, new low-k dielectric (k < 2) materials need to be developed to replace current silicon dioxide (k = 3.9) or SiCOH, etc. However, existing low-k dielectric materials, such as organosilicate glass or polymeric dielectrics, suffer from poor thermal and mechanical properties. Two-dimensional polymers (2DPs) are considered promising low-k dielectric materials because of their good thermal and mechanical properties, high porosity and designability. Here, we report a chemical-vapor-deposition (CVD) method for growing fluoride rich 2DP-F films on arbitrary substrates. We show that the grown 2DP-F thin films exhibit ultra-low dielectric constant (in plane k = 1.85 and out-of-plane k = 1.82) and remarkable mechanical properties (Young's modulus > 15 GPa). We also demonstrated the improved performance of monolayer MoS2 field-effect-transistors when utilizing 2DP-F thin films as dielectric substrates. Low-dielectric-constant (k < 2) materials are needed to reduce crosstalk, delay and power consumption in microelectronic circuits. Here, the authors report the growth of low-k 2D fluoride-rich polymer thin films, showing good mechanical properties and their application for the realization of 2D MoS2 transistors with improved performance. [ABSTRACT FROM AUTHOR]

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We thoroughly investigated the optical properties of surfactant-free deoxyribonucleic acid (SF-DNA) solid films across a broad spectral gamut from ultraviolet (UV) to terahertz (THz). Demonstrating potential as a transparent dielectric material, SF-DNA films could potentially form optical elements, such as lenses, prisms, and waveguides, for dual-band, near-IR and THz applications. SF-DNA films were classified according to their thickness. Nanometer scale films, ranging from 40 to 200 nm, were created by employing spin coating techniques with aqueous DNA solutions on silicon or fused silica substrates. Micrometer scale films, ranging from 1 to 300 μm, were formed as freestanding DNA films using drop-casting methods. Additionally, we have achieved the successful fabrication of an SF-DNA solid cylinder, positioned between two optical fiber ends, featuring a diameter of 100 to 110 μm and an axial length of 65 to 200 μm. SF-DNA films exhibited a unique dual-band transparency in the near-IR spectral range of 1260 to 1870 nm, and in the terahertz range of 0.22 to 0.64 THz. The refractive index dispersion of nanometer-scale films and their birefringence were also measured in the range of 400 to 2,600 nm. The systematic analysis of optical characteristics from UV to THz wavelengths will serve as a critical foundation for further applications of SF-DNA films in the photonic and optoelectronic device fields. [ABSTRACT FROM AUTHOR]

This study explores the surface plasmon resonance (SPR) and the electromagnetic field responses of multi-layer structures with incident light to enhance the sensitivity and range for measurement of nanoscale thin liquid film thickness. We assess the effect of metal layer type and its corresponding thickness on the optical responses. Notably, the silver (Ag) layer exhibits a more acute reflectance curve with a thickness of 50 nm, which is attributable to the minimization of non-radiative losses and a substantial real component of the dielectric constant of the Ag layer. Furthermore, a correlation between liquid film thickness and reflectance has been established across different metal layer types at specified thicknesses. The Ag layer demonstrates the broadest measurement range for liquid film thickness due to its extensive penetration depth into the dielectric material. Conversely, the sodium (Na) layer presents the narrowest measurement range, albeit with the highest SPR sensitivity. [ABSTRACT FROM AUTHOR]

In this paper, the thin-film ferroelectric material equation (TFFME) which enables the propagation of solitary polarization in thin-film ferroelectric materials is investigated, and also illustrated through the nonlinear evolution equations. Ferroelectrics are dielectric materials that exhibit nonlinear behaviors in wave propagation. Thin films constructed from the ferroelectric materials are utilized in different modern electronic devices. To investigate the characteristics of new waves, the solitary wave dynamics of the mentioned equation is used in the generalized trial equation scheme. The bright and periodic solutions are obtained by semi-inverse variational principle scheme. Many alternative responses may be obtained through different formulae; each of these solutions offers a distinct graph. The validity of such methods and solutions may be demonstrated by assessing how well the relevant techniques and solutions match up. The effects of free variables on the behavior of few achieved solutions for nonlinear rational exact cases are also plotted and explored depending upon the nature of nonlinearities. The dynamic properties of the obtained results are shown and analyzed by some density, two- and three-dimensional images. The results provide a way for future research on generating optical memories based on the nonlinear solitons. [ABSTRACT FROM AUTHOR]

The potential of HfO 2 as a memory semiconductor material with ferroelectric properties in thin-film deposition has been recently analyzed. In this study, the preparation, composition, and physical properties of Al-doped hafnium oxides were analyzed. Hf x Al (1- x) O y (HAO) [ x = 0.33, 0.5, and 0.67] powders were prepared by controlling the ratio of Hf to Al and using ball milling. The HAO powder was calcined at 1000 °C in a furnace and then sintered in a temperature range of 1000–1600 °C by a solid-state reaction method to fabricate high-quality targets with high densities. The density and crystal size increased with the sintering temperature. The 1600-°C Hf 0.67 Al 0.33 O y target was optimal for thin-film deposition. In addition, the target properties were affected by an increase in the HfO 2 content x. The crystal structures and sizes, surface free energies, contact angles, and band gaps of the HAOs were evaluated to analyze their potential as high- k dielectric materials. HAO is a promising high- k dielectric and memory material, valuable for further studies on ferroelectric gate oxide materials. This study contributes to the increasing number of studies on the ferroelectricity of HfO 2 thin films and provides a fundamental understanding of this material and its potential for novel device applications. [ABSTRACT FROM AUTHOR]

Herein two stacked nanosheets of lanthanum and silver coated by the thermal evaporation technique under a vacuum pressure of 10–5 mbar are used to form Ag2La compound. Ag2La thin films exhibited crystalline orthorhombic structure with lattice parameters, crystallite sizes and defect densities of a = 6.670 Å, b = 10.386 Å, c = 7.485 Å, 29 nm and 3.99 × 1011 lines/cm2, respectively. The films showed an indirect band gap of 3.25 eV. The band gap contained energy band tails of widths of 0.75 eV. In addition, the dielectric dispersion analyses on the Ag2La film have shown their excellent performance as high k dielectric materials displaying high dielectric constant value of 9.5 at incident light energy of 2.12 eV. On the other hand the optical conductivity and terahertz cutoff frequency spectral analyses have shown that Ag2La films have potentials applications in terahertz technology. The terahertz cutoff frequency varied in the range of 2–9 THz based on the driving light signal energy. As optical resonators they showed high sensitivity to visible and ultraviolet light signals. A respective high drift mobility of ~ 1.5 cm2/Vs and 44 cm2/Vs are estimated for the semitransparent Ag2La terahertz optical filters. The simplicity of producing Ag2La compound, the high dielectric constant values and the semiconducting characteristics of this compound make it attractive for high k-dielectric devices and for terahertz technology applications. [ABSTRACT FROM AUTHOR]

In this paper, the thin-film ferroelectric material equation (TFFME), which enables the propagation of solitary polarisation in thin-film ferroelectric materials is investigated, will be expressed through the non-linear evolution models. Ferroelectrics are dielectric materials that explain wave propagation non-linear demeanors. The non-linear wave propagation form is administrated by TFFME. To investigate the characterisations of new waves and solitonic properties of the TFFME, the modified exponential Jacobi technique and rational exp(−ϕ(η))-expansion technique are used. Plenty of alternative responses may be achieved by employing individual formulas; each of these solutions is offered by some plain graphs. The validity of such schemes and solutions may be exhibited by assessing how well the relevant schemes and solutions match up. The effect of the free variables on the manner of acting of reached plots to a few solutions in the exact forms was also explored depending upon the nature of non-linearities. The descriptive characteristics of the reached results are presented and analysed by some density, two- and three-dimensional figures. We believe that our results would pave the way for future research generating optical memories based on non-linear solitons. [ABSTRACT FROM AUTHOR]

Tunable dielectric materials have extensive applications in various fields; however, existing materials incorporate toxic elements or exhibit poor performance. Bi 1.5 MgNb 1.5 O 7 (BMN), a Bi-based pyrochlore material, can potentially overcome these obstacles; however, it has not yet been fully characterized. In this study, the influence of annealing temperature on crystallinity and electrical properties of BMN thin films was investigated, and X-ray diffraction (XRD) results indicated that the BMN films exhibited a cubic pyrochlore structure. The surface roughness of the thin films significantly decreased and uniform grain growth was achieved after annealing at 600 °C. Interestingly, energy-level peaks corresponding to metallic Bi were found in the XPS spectra of the as-deposited BMN film. As the annealing temperature was increased to 300 °C, the metallic peak completely disappeared, providing crucial evidence for the improvement of the electrical properties of BMN after annealing. The BMN films prepared in this study exhibited significant dielectric relaxation, which is closely related to the occurrence of displacement disorder. The (442) plane identified via XRD serves as a characteristic feature of displacement disorder. The film annealed at 600 °C exhibited outstanding electrical properties, with an obtained dielectric constant, energy storage density, and tunability of 204, 1.44 J/cm3, 13.1 %, respectively. These results indicate that BMN has a strong potential for application in dielectric and energy storage devices. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO2) with advantages including abundance in earth, nontoxicity, high chemical stability, surface hydrophobicity in dark, and extremely high permittivity could be highly promising for advanced electronics. However, the thermal stability and low bandgap (Eg) of TiO2 pose a big challenge for TiO2 to be used as dielectric, which could be resolved by doping with other metal cations. In this work, we studied the impact of gallium incorporation on electrical and material characteristics of TiO2 thin films. These TiO2 and TiXGaO films with thickness of 15 nm were derived by atomic layer deposition (ALD) and then annealed in O2 ambient at 500°C, where the levels of Ga incorporation were tuned by the cycle ratio (X) of TiO2 to that of Ga2O3 during ALD growth. Both thin film transistors (TFTs) using TiXGaO (TiO2) thin films as the channel and metal-oxide semiconductor capacitors (MOSCAPs) using TiXGaO (TiO2) thin films as the dielectric were fabricated to unravel the impact of Ga incorporation on electrical properties of TiO2 thin films. It is found that the Ga incorporation reduces the conductivity of TiO2 thin films significantly. Pure TiO2 thin films could be the ideal channel material for TFTs with excellent switching behaviors whereas Ga-incorporated TiO2 thin films could be the dielectric material for MOSCAPs with good insulating properties. The leakage current and dielectric constant (k) value are also found to be decreased with the increased Ga content in TiXGaO/Si MOSCAPs. Additionally, the density of interface trap (Dit) between TiXGaO and Si were extracted by multi-frequency conductance method, where a "U-shape" trap profile with similar level of Dit values can be observed for TiXGaO MOSCAPs with varying Ga contents. Material characterizations show that the Ga incorporation destabilizes the crystallization and enlarges the bandgap (Eg) of TiO2 while maintaining a smooth surface. Interestingly, Ga incorporation is found to decrease the overall oxygen content and introduce more oxygenrelated defects in the film. As a result, the reduction of leakage current upon Ga incorporation in MOSCAPs could be explained by amorphization of the film and enlarged band offset to Si rather than oxygen defect passivation. These Gaincorporated TiO2 films may found promising usage in future electronic device applications such as trench capacitors in dynamic random-access memory, where the emerging high-k dielectrics with low leakage currents and high thermal stability are demanded. [ABSTRACT FROM AUTHOR]

In the present paper, composite thin films of barium strontium titanate (BaxSr1−xTiO3) with an acceptor modifier (magnesium oxide—MgO) were deposited on metal substrates (stainless steel type) using the sol–gel method. The composite thin films feature BaxSr1−xTiO3 ferroelectric solid solution as the matrix and MgO linear dielectric as the reinforcement, with MgO concentrations ranging from 1 to 5 mol%. Following thermal treatment at 650 °C, the films were analyzed for their impedance response. Experimental impedance spectra were modeled using the Kohlrausch–Williams–Watts function, revealing stretching parameters (β) in the range of approximately 0.78 to 0.89 and 0.56 to 0.90 for impedance and electric modulus formalisms, respectively. Notably, films modified with 3 mol% MgO exhibited the least stretched relaxation function. Employing the electric equivalent circuit method for data analysis, the "circle fit" analysis demonstrated an increase in capacitance from 2.97 × 10−12 F to 5.78 × 10−10 F with the incorporation of 3 mol% MgO into BST-based thin films. Further analysis based on Voigt, Maxwell, and ladder circuits revealed trends in resistance and capacitance components with varying MgO contents, suggesting non-Debye-type relaxation phenomena across all tested samples. [ABSTRACT FROM AUTHOR]

Boron nitride (BN) is a layered two-dimensional insulator with excellent chemical, thermal, mechanical, and optical properties. We present a comprehensive characterization of hBN as a dielectric thin film using a high impedance measurement system (100 T Ω) to reveal the AC conductivity and dielectric properties of reactively RF sputtered 200 nm thick films to 480 °C. The experimental results are analyzed with reference to various theoretical models proposed for electrical conduction in disordered or amorphous semiconductors. Electrical measurements indicate that the mechanism behind hBN AC conductivity is via correlated barrier hopping (CBH) and is assigned to localized states at the Fermi level, where N(EF) ∼ 1018 eV−1 cm−3. Our measurements also reveal a σ dc component, with resistance reducing from ∼1010 Ω (50 °C) to 3 × 108 Ω (480 °C). Single RC parallel circuit fits to Cole–Cole plots are achieved signifying a sole conduction path with capacitance values of ∼8 × 10−11 F. These findings may be of interest to material and device scientists and could open new pathways for hBN both as a dielectric material encapsulant and for semiconductor device applications including high-temperature operation. [ABSTRACT FROM AUTHOR]

We investigated the synthesis of amorphous aluminum titanium oxide Al1−xTixOy thin films from a Al(acac)3 and Ti(acac)4 mixture using CH3OH/H2O as a solvent through mist chemical vapor deposition (mist-CVD) for application as a high dielectric material. The Ti composition ratio x in the Al1−xTixOy thin films depends on the Al(acac)3 and Ti(acac)4 mixing ratios and CH3OH/H2O volume ratio. A bandgap energy of Al1−xTixOy films was decreased from 6.38 to 4.25 eV and the surface roughness also decreased when the Ti composition ratio was increased from 0 to 0.54. The capacitance–voltage plot revealed that the dielectric constant of Al1−xTixOy thin films increased from 6.23 to 25.12. Consequently, Al1−xTixOy thin films with a bandgap energy of 5.12 eV and a dielectric constant of 13.8 were obtained by adjusting the ratio x of 0.26. This Al0.74Ti0.26Oy layer was applied as a gate dielectric layer for metal-oxide-semiconductor field-effect transistors (MOSFETs) using a mechanically exfoliated two-dimensional (2D) transition metal dichalcogenide (TMDC), MoSe2, and As-doped WSe2 flakes as a channel layer. The MoSe2-based MOSFETs with source/drain gold electrodes exhibit n-channel behavior with a field-effect mobility of 85 cm2/(V s), a threshold voltage of 0.92 V. On the other hand, an on/off ratio of ∼106. As-doped WSe2-based MOSFETs with source/drain platinum electrodes also showed an ambipolar behavior, which was applied for use in logic applications. These findings suggest that Al0.74Ti0.26Oy by mist-CVD is promising as a high-k material for TMDC-based MOSFETs. [ABSTRACT FROM AUTHOR]

Enhancing the energy storage performance of dielectric material through the adoption of a novel domain strategy is highly desirable. In this study, Bi0.5Na0.5TiO3‐based thin films are fabricated with topological vortex domains (VDs) by controlling the grain size and investigated the correlation between these VDs and the macroscopic polarization response, which is crucial for the energy storage performance. The emergence of VDs, in contrast to conventional ferroelectric domains, promotes polarization reversal in dielectric materials. Additionally, in contrast to the severely reduced saturation polarization typically noted in conventional relaxor ferroelectrics (RFE), the presence of VDs in RFE leads to only a slight reduction in saturation polarization. These two advantages contribute to the superior energy storage performance of the films with VDs. This approach offers a novel and promising direction for developing dielectrics with high‐energy storage capabilities. [ABSTRACT FROM AUTHOR]

Dielectric capacitors are desired for electronics and electrical power systems because of their fast charge–discharge speed and high‐power density. Nevertheless, dielectric capacitors typically exhibit lower energy densities in comparison to other energy storage systems like batteries or fuel cells. Among dielectrics, antiferroelectrics have shown great promise for high energy density because of their characteristic double hysteresis loops. However, current antiferroelectric capacitors still face challenges of low efficiency and low breakdown strength due to their large hysteresis, which is harmful to energy efficiency and reliability of the system. Herein, by engineering the nanoscale heterogeneity to mitigate hysteresis and controlling orientation to enhance the polarization, the exceptional energy storage performance of antiferroelectric (Pb0.97La0.02)(Zr0.55Sn0.45)O3 epitaxial thin films is demonstrated. Atomic‐resolution transmission electron microscopy and X‐ray reciprocal space mapping confirm the presence of nanoscale structural heterogeneity, characterized by fragmented antipolar nanodomains. These films exhibit remarkable energy densities, reaching up to ≈84.5 J cm−3, coupled with ultrahigh efficiencies of up to ≈98.5% and superior stability, maintaining efficiencies above 92% across a wide field range of ≈5 MV cm−1. Notably, these findings surpass the capabilities of previously reported dielectric materials, opening new avenues for advanced energy storage applications. [ABSTRACT FROM AUTHOR]

To replace SiO2 as gate dielectrics in complementary metal‐oxide‐semiconductor‐compatible microelectronic devices, research on alternative high‐k dielectric materials is deeply focused. Although high‐k dielectrics have high permittivity, it suffers from poor electrical quality due to the presence of charge densities during the deposition process. To suppress these charge densities, there is an urge for a suitable fabrication process. Herein, radio frequency magnetron sputtering is used to deposit Ta2O5 thin films on p‐type Si. During deposition, sputtering pressure and Ar/O2 gas flow ratio are varied systematically. Postdeposition annealing is carried out for an hour at 900 °C in air ambient. The microstructural, morphological, and electrical properties are studied from X‐ray diffraction (XRD), Fourier transform infrared spectroscopy, atomic force microscopy (AFM), capacitance–voltage, and current–voltage characteristics. XRD reveals orthorhombic β‐phase structure of the film annealed at 900 °C. The AFM micrographs show that the roughness of the film increases with the increase in both sputtering pressure and Ar/O2 gas flow ratio. The oxide charge density (Qox), interface charge density (Dit), and leakage current are found to be decreased with the increase in both Ar/O2 gas flow ratio and sputtering pressure. [ABSTRACT FROM AUTHOR]

This article presents a wide-angle-scanning leaky-wave antenna (LWA) based on a composite right/left-handed (CRLH) transmission line. In contrast to traditional semiconductor elements, thin-film ferroelectric capacitors were implemented in the CRLH unit cells to enable electric beam scanning. The proposed CRLH LWA has a single-layer design without metalized vias and is compatible with PCB and thin-film technologies. To fabricate the CRLH LWA prototype, dielectric material substrates and thin-film ferroelectric capacitors were manufactured, and their characteristics were investigated. Double-sided metalized fluoroplast-4 reinforced with fiberglass with a permittivity of 2.5 was used as a substrate for CRLH LWA prototyping. A solid solution of barium strontium titanate (Ba x Sr 1 − x TiO 3 ) with a composition of x = 0.3 was used as a ferroelectric material in electrically tunable capacitors. The characteristics of the manufactured ferroelectric thin-film capacitors were measured at a frequency of 1 GHz using the resonance method. The capacitors have a tunability of about two and a quality factor of about 50. The antenna prototype consists of ten units with a total length of 1.25 wavelengths at the operating frequency of close to 2.4 GHz. The experimental results demonstrate that the main beam can be shifted within the range of −40 to 16 degrees and has a gain of up to 3.2 dB. The simple design, low cost, and excellent wide-angle scanning make the proposed CRLH LWA viable in wireless communication systems. [ABSTRACT FROM AUTHOR]

In this paper, the design and optimization of a wideband THz metamaterial absorber (MMA) are proposed. By simulation, we reached four structures with absorptions higher than 50%, 70%, 80%, and 90%, with relative absorption bandwidths (RABWs) of 1.43, 1.29, 0.93, and 0.72, respectively. Terahertz absorbers can be used in many potential applications, such as in imaging, energy harvesting, scattering reduction, and thermal sensing. Our intended application was to use the optimal absorber on a thermal detector for detectivity over a wide THz range. Since broadband absorption in the range of 0.3 to 2 terahertz is considered for use in medical imaging, the MMA with more than 50% absorption in the range of 0.35-2.1 THz was selected. The designs were also intended to have the capability of being implemented on different devices, such as bolometers. The cost of the fabrication of the proposed absorber was also low because of the implementation of a single-layer MMA design and the utilization of affordable and more accessible materials and techniques. Our proposed structure had a minimum feature size of 3 μm, making the fabrication process convenient using the standard photolithography method as well. We used thin layers of nickel as the metal for both the single-layer pattern and ground layer, which were placed on the front and back sides of the structure, respectively. The nickel thin film layers were deposited using the sputtering technique and separated by a dielectric layer. The material chosen for the dielectric layer was SU8, which has proper electromagnetic properties and also good adhesion to nickel. Characterization of the fabricated absorber was performed using a terahertz spectroscopy system, and the experimental results verified the high absorption of the sample. [ABSTRACT FROM AUTHOR]

Optimizing dielectric energy storage often involves increasing ferroelectric polarization and breakdown strength while delaying polarization saturation. Here, we investigated another factor named polarization difference Δ P to explore its effect on energy storage density of dielectric materials. The nominal compositions of [Bi 0.75 (Bi 0.5 Na 0.5) 0.25 ](Mg 0.375 Ti 0.625 x)O 3 with excess Ti were selected to investigate dielectric energy characteristics. The excess Ti sources were found to effectively optimize the dielectric characteristics, with the highest E b of 3382 kV/cm at x = 1.16 and the largest Δ P of 144 μC/cm2 at x = 1.24, respectively. Interestingly, the highest energy density of 141 J/cm3 (x = 1.24) was achieved at E b = 2955 kV/cm rather than the maximum E b , indicating a synergistic effect of polarization and dielectric breakdown. This means that tailoring Δ P can be another effective strategy for customizing the energy storage characteristics of electrostatic dielectric capacitors. [ABSTRACT FROM AUTHOR]

The polymer composite Bismuth Titanate based lead-free binary system Nylon-11/0.75Bi0.5Na0.5TiO3-0.25SrTiO3 (N11/BNTST) has been developed using the solution casting method in different ratio for advanced energy system. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) were used to confirm the structure. XRD pattern of all samples shows the N11 and rhombohedral phase of BNT-ST with the presence of both phases for the composite. The surface microstructure of a nanocomposites film with a 70:30 N11:BNT-ST composition reveals homogenous BNT-ST nanoparticle dispersion in Nylon-11 matrix with negligible holes. However, compositions with a larger percentage of BNT-ST show agglomeration with a large number of pores, which lowers the dielectric constant and increases dielectric loss. At room temperature, the electrical characteristics of the produced N11/BNT-ST composite are examined periodically. The dielectric behavior of the materials exhibit a decrease in dielectric constant as well as loss with increasing frequency. The experimental data of the N11/BNTST, comparing the pure N11 polymer film to composite, the dielectric characteristics have significantly improved. The maximum dielectric response has been observed for 70N11-30BNTST composition. So, N11/BNTST composite has been shown to be a viable option for applications requiring electronic capacitive energy storage. [ABSTRACT FROM AUTHOR]

This work analyzed and compared the optical and photoenergetic properties of low-emissivity coatings made from various dielectric materials deposited through magnetron sputtering following a systematic, comparable method. Different multilayer structures of silver-based low-emissivity coatings were studied using SnO2, ZnO, SiAlNx, and aluminum-doped zinc oxide (AZO, which is inherently a semiconductor, but it fulfils an optical dielectric function in this type of structure). The properties of the coatings were determined by spectrophotometric and sheet resistance measurements. Coatings with AZO as the dielectric layers obtain the best photoenergetic performance because silver growth is more efficient on AZO. We also studied the effect of ion bombardment on AZO and SiAlNx in an attempt to obtain a better low-emissivity coating, achieving better results when etching the dielectric layer with an ion gun. Regarding the structures' visible transmission, the oxides produced better transmission results. Based on the above, we concluded that AZO had the best optical and photoenergetic properties in our deposition system, observing, in the best-case scenario, improvements in emissivity from 0.083 with SnO2 to 0.058 with AZO and to 0.052 using an ion beam on AZO and improvements in visible transmission from 81.9% with SnO2 to 86.8% with AZO. [ABSTRACT FROM AUTHOR]

For continual scaling in microelectronics, new processes for precise high volume fabrication are required. Area-selective atomic layer deposition (ASALD) can provide an avenue for self-aligned material patterning and offers an approach to correct edge placement errors commonly found in top-down patterning processes. Two-dimensional transition metal dichalcogenides also offer great potential in scaled microelectronic devices due to their high mobilities and few-atom thickness. In this work, we report ASALD of MoS2 thin films by deposition with MoF6 and H2S precursor reactants. The inherent selectivity of the MoS2 atomic layer deposition (ALD) process is demonstrated by growth on common dielectric materials in contrast to thermal oxide/ nitride substrates. The selective deposition produced few layer MoS2 films on patterned growth regions as measured by Raman spectroscopy and time-of-flight secondary ion mass spectrometry. We additionally demonstrate that the selectivity can be enhanced by implementing atomic layer etching (ALE) steps at regular intervals during MoS2 growth. This area-selective ALD process provides an approach for integrating 2D films into next-generation devices by leveraging the inherent differences in surface chemistries and providing insight into the effectiveness of a supercycle ALD and ALE process. [ABSTRACT FROM AUTHOR]

Single-crystalline high-κ dielectric materials are desired for the development of future two-dimensional (2D) electronic devices. However, curent 2D gate insulators still face challenges, such as insufficient dielectric constant and difficult to obtain free-standing and transferrable ultrathin films. Here, we demonstrate that ultrathin Bi2SiO5 crystals grown by chemical vapor deposition (CVD) can serve as excellent gate dielectric layers for 2D semiconductors, showing a high dielectric constant (>30) and large band gap (~3.8 eV). Unlike other 2D insulators synthesized via in-plane CVD on substrates, vertically grown Bi2SiO5 can be easily transferred onto other substrates by polymer-free mechanical pressing, which greatly facilitates its ideal van der Waals integration with few-layer MoS2 as high-κ dielectrics and screening layers. The Bi2SiO5 gated MoS2 field-effect transistors exhibit an ignorable hysteresis (~3 mV) and low drain induced barrier lowering (~5 mV/V). Our work suggests vertically grown Bi2SiO5 nanoflakes as promising candidates to improve the performance of 2D electronic devices. Crystalline high-κ dielectric materials are desired for the development of future 2D electronic devices. Here, the authors report the in-plane and out-of-plane chemical vapor deposition growth of ultrathin Bi2SiO5 crystals with dielectric constant >30 and a band gap of ~3.8 eV, showing their effective application as gate dielectric layers of MoS2 transistors. [ABSTRACT FROM AUTHOR]

We present the results of an experimental investigation of polystyrene's suitability as a dielectric material for designing narrowband, infrared metasurface-based absorbers. Our study included characterization of processing parameters of polystyrene films, such as surface roughness and film thickness, which are critical for device fabrication, and the dielectric properties, which we measured, using spectroscopic ellipsometry. Our results confirm that thin film polystyrene is a relatively low-loss dielectric material at long-wave infrared (LWIR) frequencies. Subsequently, this material was used as the dielectric substrate of a thin, narrowband, metasurface-based absorber at LWIR frequencies. The fabricated narrowband absorber demonstrates excellent performance in the LWIR band with absorptivity as high as 96% and a full-width-at-half-maximum bandwidth of 0.502 μ m or 4.87%. [ABSTRACT FROM AUTHOR]

Biopolymers obtained from renewable resources became the center of public interest by virtue of their environmental and commercial advantages. Natural polymers such as starch, almond gum, chitosan and arabic gum were investigated to get fully or partially biodegradable dielectric material. Thus, in this article we study the material properties of cashew gum. This biopolymer is an exudate collected from occidental anacardium tree. For this investigation, scanning electron microscopy of powder and thin film cashew gum showed homogenous and slightly rough surface morphology with visible wrinkles. The thermal analyses such as thermogravimetric (TGA) and differential scanning calorimeter were realized. thermogravimetric thermogram shows two distinct stages of decomposition. The first around 150°C is attributed to moisture evaporation with loss in weight of 9.7%. The second transition, between 255°C and 330°C, is related to the decomposition of cashew gum with loss in weight of 50%. UV-visible spectra of the cashew gum thin film show a low absorbance and high transmittance. For this material, we obtained a direct optical band gap around 4.56 eV. In addition, the dielectric and electrical characterizations lead to conclude that cashew gum may be interesting for transistor applications as a gate dielectric. [ABSTRACT FROM AUTHOR]

Dielectric materials that can withstand high voltages are of great interest due to the growing need for high‐performance insulation systems in electronics. Polymer nanocomposites have gained popularity as electrical insulators due to their processability, high operating voltage, and tortuous paths for current flow created by the nanoparticles in the polymer matrix. The dielectric breakdown strength of a relatively thick multilayer thin film containing polyethylenimine (PEI) and vermiculite clay (VMT), thickened with tris(hydroxymethyl)aminomethane (tris), is evaluated as a function of bilayers (BL) deposited. The resulting nanobrick wall structure of this clay‐based assembly is ideal for protective insulation. An 8 BL PEI+tris/VMT film achieves a dielectric breakdown strength of 245 kV mm−1, with a thickness of 5 µm. With increasing bilayers, the breakdown strength gradually decreases, but 20 BL of PEI+tris/VMT achieves a breakdown voltage of 2.36 kV. This nanoplatelet‐based system is the first "thick growing" layer‐by‐layer deposited film to be used as an insulating layer. Its unusually high breakdown strength can be useful for the protection of various high voltage electronics. [ABSTRACT FROM AUTHOR]

SrTiO3 (STO), a room-temperature paraelectric material in bulk form, has been a rich playground for emergent phenomena for decades. As an emerging material, great attention has been paid to freestanding 2D STO thin films. Recently, the room-temperature ferroelectricity has been unveiled in strained STO thin films; however, it remains an open question whether the strain-free freestanding 2D STO thin film is room-temperature ferroelectric or not. Here, we report the electric field-induced out-of-plane ferroelectric polarization in large-scale, freestanding, and strain-free 2D STO membranes at room temperature. High-resolution piezoresponse force microscopy measurements show that polarization in freestanding strain-free STO membranes can be switched by electric field and persist for an hour. The first-principles calculations suggest that the intrinsic defects such as oxygen vacancies could be linked to the observed spontaneous out-of-plane polarization in 2D STO membranes, which could be further enhanced by external electric field due to the induced symmetry breaking. Our work reports the unprecedented room-temperature ferroelectric polarization in strain-free freestanding 2D STO membranes, unlocking the great potential of freestanding 2D STO for the applications in novel electronic and logic-in-memory devices. [ABSTRACT FROM AUTHOR]

Polarization and breakdown strength as two sides of one coin are difficult to balance in one dielectric material, and so hierarchical heterostructure would be a good way to combine the advantages of each material enhancing energy density. In this work, high polarization Bi(Mg 0.5 Zr 0.5)O 3 (BMZ) and high breakdown strength Ba(Zr 0.25 Ti 0.75)O 3 (BZT) are chosen to prepare 1BMZ/4BZT/1BMZ (Type-A), 3BMZ/3BZT (Type-B) and 3(BMZ/BZT) (Type-C) hierarchical heterostructures thin films on Pt/Ti/SiO 2 /Si substrate via sol-gel method. Microstructure characteristics of thin films indicate that they possess well density, no crack and smooth surface. Thin films with Type-B structure possess a high dielectric constant of ∼500, which exceeds ∼150 of that with Type-A and Type-C structures. For energy storage properties, Type-B and Type-C thin films achieve high recoverable energy density W rec of 85.6 J/cm3 and 85.7 J/cm3 at low field of 2545 kV/cm and high field of 4980 kV/cm, respectively. The design of hierarchical heterosrtucture would break the limitation of low energy density in single material, and provide a new thinking for the applications of dielectric energy storage materials. Synergistic function of hierarchical heterostructure design and chemical composition selection to enhance energy storage properties at different electric fields. [Display omitted] [ABSTRACT FROM AUTHOR]

Electrospray deposition (ESD) uses strong electric fields to produce generations of monodisperse droplets from solutions and dispersions that are driven toward grounded substrates. When soft materials are delivered, the behavior of the growing film depends on the film's ability to dissipate charge, which is strongly tied to its mobility for dielectric materials. Accordingly, there exist three regimes of electrospray: electrowetting, charged melt, and self-limiting. In the self-limiting regime, it has been recently shown that the targeted nature of these sprays allows for corona-free 3D coating. While ESD patterning on the micron-scale has been studied for decades, most typically through the use of insulating masks, there has been no comparative study of this phenomenon across spray regimes. Here, we used test-patterns composed of gratings that range in both feature size (30–240 μm) and spacing (⅓x–9x) to compare materials across regimes. The sprayed patterns were scanned using a profilometer, and the density, average height, and specificity were extracted. From these results, it was demonstrated that material deposited in the self-limiting regime showed the highest uniformity and specificity on small features as compared to electrowetting and charged melt sprays. Self-limiting electrospray deposition is, therefore, the best suited for modification of prefabricated electrode patterns. [ABSTRACT FROM AUTHOR]

• An innovative micro hybrid capacitor is realized using Ta2O5 thin films and MnO2 composite electrodes. • This devices has been successfully tested in ionic liquid and ionogel electrolytes. • The device provides a cell voltage 20 v and cycles stable up to 5000 mV s-1. • 2000 cycles at 500 mV s-1 have been reached. • The performance of ionic liquid and ionogel is very comparable highlighting the promising application of ionogels even for miniaturized high power devices. In this work, we present a new cell design for miniaturized energy storage devices by realizing a hybrid micro-capacitor, which uses for the first time a TaN/ Ta 2 O 5 thin film electrode in combination with a MnO 2 composite electrode. In this proof of concept study, the electrochemical performance of the dielectric material Ta 2 O 5 was of main interest. Therefore, various tantalum oxide films with different thicknesses from 23 to 80 nm have been tested in combination with a pseudocapacitive oversized MnO 2 composite electrode. This was done with two model electrolytes, namely the ionic liquid Emim FSI and the solid-state ionogel Emim FSI: PVdF 80:20. Surface capacitance values up to 1.94 µF cm-2 in Emim FSI and 2.84 µF cm-2 in IG Emim TFSI: PVdF 80:20 have been reached at high scan rates (100 mV s-1) with no significant distortion of the voltammograms. When films of 47 and 80 nm thickness of Ta 2 O 5 are used, stable cycling with scan rates of up to 5000 mV s-1 at a cell voltage of 20 V can be achieved even in solid-state ionogel electrolyte. This performance highlights the promising characteristics of these materials and cell concept for miniaturized high power energy storage application and opens the way for further investigations to improve this needed technology. [Display omitted] [ABSTRACT FROM AUTHOR]

Surface plasmon resonance (SPR)-based sensors are widely used to measure thin film thickness, material dielectric constants, biomolecular interactions, and more. However, conventional monochromatic setups limit the simultaneous determination of dielectric constant dispersion and film thickness. To address this, we developed a fully automated wavelength-resolved SPR using a double-prism Kretschmann configuration. Combining this setup with a computational approach based on Fresnel equations and the Nelder-Mead optimization method, we introduced a novel technique to simultaneously determine the dispersion (520–1000 nm) of the real and imaginary components of the dielectric constant of thin films directly from SPR curves. As far as we know, this is the first time an SPR spectrometer has accomplished such a remarkable achievement. As a proof of concept for biosensor applications, we determined the thickness and dielectric constant dispersion of gold and bovine serum albumin thin film. These thicknesses were validated through atomic force microscopy, and the dielectric constants aligned closely with literature values obtained by ellipsometry. The developed SPR system enables precise measurements of these parameters within a short time (10 minutes), paving the way for future applications in advanced sensors and biosensors. [Display omitted] • This paper introduces an innovative SPR spectrometer that accurately determines the thin film dielectric constant dispersion and thickness. • We developed an approach to simplify the SPR spectrometer, increase reproducibility, and provide wavelength-resolved optical response. • Our findings are validated against established techniques like AFM and ellipsometry. • The developed SPR spectrometer opens new avenues for characterizing the fundamental aspects of surface plasmon in several materials. [ABSTRACT FROM AUTHOR]

For Bi1.6Pb0.4Sr2Ca2Cu3-xZnxO superconductor films, the dielectric constant value at x = 0, 0.2, 0.4, and 0.6 was obtained by building a theoretical relation between the dropping off voltage that scaled during the electrical resistivity measurements using four-point probe technique with dielectric constant. The results showed that the dielectric constant has an inverse relation with the voltage due to a film's ability to concentrate electric field lines across the BiPbSrCa layer. The increment of the Zn partial substitution in the Cu site revealed a dielectric constant value decrease with the voltage, which is noted at x = 0.4 and 0.6. This may relate to the pinholes increase in the BiPbSrCaCuZnO film that covers a range of defects in the film. The pinholes' existence in the films had a direct influence on the dielectric strength of BiPbSrCaCu material. The dielectric material's conductivity correlated to the hopping transition of the defect charge carriers and was strongly annealing temperature dependent. [ABSTRACT FROM AUTHOR]

Herein, thin films of magnesium selenide are thermally grown in a vacuum deposition (VD) system onto glass substrates under a vacuum pressure of 10–5 mbar. The films are structurally, morphologically, compositionally, and optically characterized. It is observed that MgSe thin films coated by the VD technique are composed of polycrystalline MgSe1.07 (a = 5.149 Å, space group F m 3 m ) and MgSe1.96 (a = 6.514 Å, space group P 3 - a ) cubic phases. The films displayed an average roughness value of 13 nm. They also exhibited a direct energy band gap of 2.54 eV and an indirect band gap of 3.34 eV. In addition, detailed studies of the dielectric properties, optical conductivity, and terahertz cutoff frequency spectra showed the ability of MgSe thin films to perform as a dielectric material. High dielectric constant values are reached in the near-infrared range of light. As optical conductors, the films displayed one IR, two visible, and two ultraviolet light oscillators showing a maximum plasmon frequency of 8.19 GHz in the UV range. The drift mobility of these oscillators varied in the range of 4.57–9.67 cm2/Vs. Moreover, the terahertz cutoff frequency for these oscillators varied in the range of 11–175 THz proofing the suitability of MgSe films for terahertz technology issues. [ABSTRACT FROM AUTHOR]

Flexible dielectric materials are widely explored and used for energy storage applications. In this paper, we present a research work on the development of new flexible dielectric films by combining poly(vinyl alcohol) (PVA) used as flexible polymer matrix and reduced grapheme oxide (rGO) and barium titanate (BaT) added in different ratios to tailor their capacitance. The properties of resultant nanocomposite films have been tailored based on the properties of their constituents; flexibility of the PVA, high thermal stability better dielectric properties due to both fillers i.e., rGO and BaT. The synthesized nanocomposite films prepared by different ratio of these three components were characterized for their structural, chemical, morphological, thermal, and dielectric properties. Their dielectric studies carried using impedance analyzer at room temperature revealed that nanocomposite with rGO:barium titanate:poly(vinyl alcohol) = 0.3:2.5:10 shows excellent real part of permittivity of 66 at 20 Hz which decreased to 10.9 at very high frequency of 2 MHz and low energy loss of 0.8 at 20 Hz which was reduced to 0.06 at 2 MHz. Also energy storage capacity of nanocomposites was calculated, and it was found that rGO:barium titanate:poly(vinyl alcohol) = 0.3:1:10 showed best energy storing properties with total energy density, recoverable energy density, and energy loss of 2.1 × 10−4 kJ/m3, 1.5 × 10−4 kJ/m3, and 5.2 × 10−5 kJ/m3. Its efficiency was 71%. The presented synthesized flexible dielectric films with tailorable dielectric performances are very desirable for flexible capacitor sensing application due to their excellent flexibility, efficient thermal, and dielectric properties. [ABSTRACT FROM AUTHOR]

ZnO has been extensively used as oxide in the thin film electronics industry because of its performance advantages such as electrical and optical properties. This study represents the design and optimization of the ZnO thin film transistor (TFT). The characteristics of the device are studied using the software Silvaco TCAD ATLAS. The improvement in the performance of the device has been observed in optimizing dielectric layer thickness ( T ox ). Further SiO2 oxide layer is replaced with the high- k dielectric to improve its performance. The use of high- k dielectric gives the concept of equivalent oxide thickness (EOT) in which physical thickness (PT) of the dielectric layer is increased without increasing electric thickness (effective thickness), which improves the reliability of the device. The electrical parameters extracted for the low- k SiO2 (K = 3. 9) at thickness (TSiO2) 50 nm are I on = 2. 1 3 × 1 0 − 5 A, I off = 1. 4 1 × 1 0 − 1 2 A, I on ∕ I off = 1 0 7 , SS = 0. 0 7 7 V/decade, VTH = 0. 2 7 V. The high performance of the device has been achieved using Al2O3 and HfO2 as the dielectric material. This study presents the design and optimization of the ZnO thin film transistor. The characteristics of the device are studied using the software Silvaco TCAD ATLAS. The improvement in the performance of the device has been observed in optimizing dielectric layer thickness (Tox). Further SiO2 oxide layer is replaced with the high-k dielectric to improve its performance. [ABSTRACT FROM AUTHOR]

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Cross-linking polymer gate dielectric is an efficient strategy to improve its intrinsic properties for high-performance flexible organic field-effect transistors (OFETs). However, the detail optimization process of the polymer films with the various cross-linking degrees is often ignored, which can bring a significant effect on the electrical performance of OFETs. In this work, the cross-linked poly (vinylalcohol) (CPVA) is introduced as the gate dielectrics for the high-performance ultraflexible OFETs. The dielectric property and the surface property of CPVA thin films with various cross-linking degrees are investigated in detail. The OFETs with a high average mobility of 7.3 cm $^{2}\cdot V^{-1}\cdot s^{-1}$ , a current ON/ OFF ratio of over 107, and a lower density of trap states of $8.7\times10$ 11 eV $^{-1}\cdot cm^{-2}$ are achieved successfully. Moreover, the ultraflexible OFET presents a high mobility of over 5.1 cm $^{2}\cdot V^{-1}\cdot s^{-1}$ even bending around a copper wire with a small radius of $400 ~\mu \text{m}$ , due to the ultrathin thickness of the device. These results demonstrate that the CPVA thin film is a promising candidate dielectric material for flexible organic transistors, presenting huge potential for the next-generation flexible electronic devices. [ABSTRACT FROM AUTHOR]

Dielectric materials with excellent energy storage performance are urgently needed in advanced electrical power systems. We have reported that Mn2+‐doped SrTiO3 thin films have high energy storage density. However, the thin films exhibit fat polarization‐electric field hysteresis loops with high hysteresis, which is not conducive to greater energy storage performance. In this work, the Ca2+‐doped Sr1‐xCaxTi0.99Mn0.01O3 thin films are fabricated to construct slim polarization‐electric field hysteresis loops with low hysteresis for obtaining excellent energy storage performance. Because Ca2+ can break the long‐range ferroelectric order of SrTi0.99Mn0.01O3, the domain size decreases and the coupling of domains weakens, ultimately leading to low hysteresis. Moreover, doping Ca2+ can induce distortion of the octahedral [TiO6] to form local polarization regions. When doped an appropriate amount of Ca2+, local lattice distortion plays an important role in polarization behavior, which helps to enhance polarization. Meanwhile, the Ca2+‐doped thin films also possess good insulation. Finally, the higher energy storage density of 63.9 J cm‐3 is achieved in the Sr0.9Ca0.1Ti0.99Mn0.01O3 thin film. When the electric field is less than 4000 kV cm‐1, the energy storage efficiency remains above 70%. Simultaneously, a wide working temperature range from ‐100℃ to 100℃ is also obtained. [ABSTRACT FROM AUTHOR]

We report extensive enhancement in the refractive index of artificially designed metamaterials by exploiting the deep subwavelength coupling in a free-standing, thin-film metal-dielectric-metal checkboard structure. A record high refractive index of 77.02+43.22i is obtained at terahertz frequencies. The detailed investigations reveal that the enhancement of the effective refractive index of the structure via deep subwavelength coupling in a bilayer design is governed by a power law, which is an effective and simpler approach to design high index metamaterials. The approach relies on deep subwavelength coupling to obtain extremely high refractive index values that can lead to many practical applications in the field of imaging, lithography, design of delay lines, and interferometers. [ABSTRACT FROM AUTHOR]

This study describes the synthesis of barium (Ba) and strontium (Sr) thin films using jet neublizer spray pyrolysis (JNSP) technology, which facilitates the fabrication of junction diodes whose structure, surface morphology, and optical properties are affected by significant water absorption. Ba–Sr films with different strontium concentrations (specifically 0, 2, 4 and 6 wt%) were further investigated to provide a better understanding of how this change affects the final diode type. The research design focuses on fabricating n-type silicon junction diodes containing barium and strontium and directly measuring and analyzing their I–V characteristics, ultimately helping elucidate these devices' electrical behavior. Among the analyzed diodes, the Ag/Ba–Sr/n-Si/Ag diode performed well in various design tests, indicating its competitiveness due to its goodness in optoelectronic devices. The ideal value (n) of a 6 wt% Ba–Sr diode is 1.77 and the barrier height (Φ B) is 0.84 eV. These results demonstrate the general future of Ba–Sr junction diode, as they not only reveal important discoveries regarding their electrical properties but also demonstrate the potential for improved performance in optoelectronic applications. [Display omitted] • A sensitive Ag/Ba–Sr/n-Si/Ag structured junction diode was efficaciously fabricated by JNSP process. • Strangely, UV–Vis analysis revealed a smaller band gap of 3.18 eV in samples heated at higher substrate temperatures. • Especially, 6 wt% Ba–Sr produced the best diode with n = 1.77 and ϕ B = 0.84 eV. • To enhance diode performance, a high dielectric material can be introduced in the fabrication of a p-n junction diode. [ABSTRACT FROM AUTHOR]

• AgNbO 3 films grown by reactive d.c. magnetron co-sputtering from metal targets. • Effect of oxygen partial pressure and bias potential on phase formation studied. • Films deposited at floating potential form various crystalline and amorphous phases. • More energetic growth conditions lead to the formation of homogeneous AgNbO 3 films. • Significance of precise process control to counteract formation of secondary phases. The quest for environmentally sustainable alternatives to lead-based dielectric materials in dielectric capacitors has led research to the exploration of options such as silver niobate (AgNbO 3), which has been found to display excellent energy storage properties. Homogeneity and phase-purity of the used thin films are vital for optimal performance of these devices. In this study, a systematic variation of oxygen partial pressure and bias voltage during reactive d.c. magnetron co-sputtering from metallic targets is employed to synthesise AgNbO 3 thin films. Structural and chemical composition of the films are investigated using X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy, elastic recoil detection analysis, and Rutherford backscattering spectrometry. The findings emphasise the necessity of precise parameter control during deposition to avoid the presence of undesirable secondary phases like Ag and Ag 2 Nb 4 O 11 and to ensure the formation of homogeneous and phase-pure AgNbO 3 thin films. The gained insights demonstrate the potential of reactive d.c. magnetron sputtering for the deposition of lead-free AgNbO 3 thin films, offering pathways for enhanced environmental compatibility of future dielectric capacitors. [ABSTRACT FROM AUTHOR]

The main objective of this work is to propose an approach for improving the performance of miniaturized microstrip patch antennas (MPAs) that are loaded with a thin film consisting of a high relative permittivity material. The method uses a thin film to decrease the antenna's resonance frequency while keeping the antenna's patch dimensions. For the enhancement of the antenna's performance with a thin film, the dimensions of the patch of the designed antenna are optimized utilizing genetic algorithms (GAs). The resonance frequency of the microstrip patch antenna was changed from 5.8 GHz to 4.0 GHz, and the area of the proposed antenna was minimized by around 60%, especially in comparison to a conventional antenna alone without thin film. Most of the performances of the proposed antenna such as the return loss, bandwidth, and voltage standing wave ratio (VSWR) were improved. [ABSTRACT FROM AUTHOR]

Digital microfluidics (DMF) is a versatile platform for conducting a variety of biological and chemical assays. The most commonly used set-up for the actuation of microliter droplets is electrowetting on dielectric (EWOD), where the liquid is moved by an electrostatic force on a dielectric layer. Superhydrophobic materials are promising materials for dielectric layers, especially since the minimum contact between droplet and surface is key for low adhesion of biomolecules, as it causes droplet pinning and cross contamination. However, superhydrophobic surfaces show limitations, such as full wetting transition between Cassie and Wenzel under applied voltage, expensive and complex fabrication and difficult integration into already existing devices. Here we present Fluoropor, a superhydrophobic fluorinated polymer foam with pores on the micro/nanoscale as a dielectric layer in DMF. Fluoropor shows stable wetting properties with no significant changes in the wetting behavior, or full wetting transition, until potentials of 400 V. Furthermore, Fluoropor shows low attachment of biomolecules to the surface upon droplet movement. Due to its simple fabrication process, its resistance to adhesion of biomolecules and the fact it is capable of being integrated and exchanged as thin films into commercial DMF devices, Fluoropor is a promising material for wide application in DMF. [ABSTRACT FROM AUTHOR]

Ferroelectrics with a high dielectric constant are ideal materials for the fabrication of miniaturized and integrated electronic devices. However, the dielectric constant of ferroelectrics varies significantly with the change of temperature, which is detrimental to the working stability of electronic devices. This work demonstrates a new strategy to design a ferroelectric dielectric with a high temperature stability, that is, the design of a multilayer relaxor ferroelectric thin film with a composition gradient. As a result, the fabricated up-graded (Pb,La)(Zr0.65,Ti0.35)O3 multilayer thin film showed a superior temperature stability of the dielectric constant, with variation less than 7% in the temperature range from 30 °C to 200 °C, and more importantly, the variation was less than 2.5% in the temperature range from 75 °C to 200 °C. This work not only develops a dielectric material with superior temperature stability, but also demonstrates a promising method to enhance the temperature stability of ferroelectrics. [ABSTRACT FROM AUTHOR]

Purpose: Indium tin oxide (ITO) is a material belonging to the group of transparent conductive oxides, which are widely used in many fields of technology including optoelectronics and photovoltaics. However, the properties of ITO thin films depend on many factors. Therefore, the aim of the study was thorough investigation of the properties of sputtered ITO thin films of various thicknesses. Design/methodology/approach: ITO coatings were deposited by magnetron sputtering in pure argon atmosphere using ceramic ITO target. Various deposition times resulted in obtaining thin films with different thickness, which had significant influence on the optoelectronic properties of deposited coatings. In this work the results of investigation of structural, surface, optical and electrical properties were presented. Findings: Increase of the coating thickness caused change of the microstructure from amorphous to nanocrystalline and occurrence of grains with a size of 40 to 60 nm on their surface. Moreover, the fundamental absorption edge was red-shifted, whereas the average transmission in the visible wavelength range remained similar. Increase of the thickness caused considerable decrease of the sheet resistance and resistivity. It was found that even thin films with a thickness of 10 nm had antistatic properties. Originality/value: The novelty and originality of presented work consists in, among other, determination of antistatic properties of ITO thin films with various sheet resistances that are in the range typical for dielectric and semiconducting material. To date, there are no reports on such investigations in the literature. Reported findings might be very helpful in the case of, for example, construction of transparent antireflective and antistatic multilayers. [ABSTRACT FROM AUTHOR]