Conventional Electronics Research Articles

End-of-life options for printed electronics in municipal solid waste streams: a review of the challenges, opportunities, and sustainability implications

Abstract Although printed electronics (PE) are a more sustainable option than conventional electronics, proper treatment of PE in their end-of-life phase is crucial to decrease their overall environmental impacts and ensure the materials specifically the metal fraction of PE are recovered. Thus, to investigate the state of the art regarding the research and development of material recovery from PE, this study performed a literature review process. It concluded that the majority of the observed articles rather not mention specifically what is recycling option for recycling the PE or introduced a novel recycling method for the metal ink. Only a marginal fraction of the articles covered proper recycling methods for the metal fraction of PE. Then based on the literature review process, this study investigates the suitability of the current waste management system to recover different fractions of PE products.

Reversing the magnetization of 50-nm-wide ferromagnets by ultrashort magnons in thin-film yttrium iron garnet.

Spin waves (magnons) can enable neuromorphic computing by which one aims at overcoming limitations inherent to conventional electronics and the von Neumann architecture. Encoding magnon signal by reversing magnetization of a nanomagnetic memory bit is pivotal to realize such novel computing schemes efficiently. A magnonic neural network was recently proposed consisting of differently configured nanomagnets that control nonlinear magnon interference in an underlying yttrium iron garnet (YIG) film [Papp et al., Nat. Commun., 2021, 12, 6422]. In this study, we explore the nonvolatile encoding of magnon signals by switching the magnetization of periodic and aperiodic arrays (gratings) of Ni81Fe19 (Py) nanostripes with widths w between 50 nm and 200 nm. Integrating 50-nm-wide nanostripes with a coplanar waveguide, we excited magnons having a wavelength λ of ≈100 nm. At a small spin-precessional power of 11 nW, these ultrashort magnons switch the magnetization of 50-nm-wide Py nanostripes after they have propagated over 25 μm in YIG in an applied field. We also demonstrate the magnetization reversal of nanostripes patterned in an aperiodic sequence. We thereby show that the magnon-induced reversal happens regardless of the width and periodicity of the nanostripe gratings. Our study enlarges substantially the parameter regime for magnon-induced nanomagnet reversal on YIG and is important for realizing in-memory computing paradigms making use of magnons with ultrashort wavelengths at low power consumption.

(Electronics and Photonics Division Poster Award Winner) A High Breakdown Voltage Silicon Carbide (SiC)/Gallium Oxide (Ga2O3) Heterojunction Diode for High Power Applications

Wide and ultrawide bandgap semiconductors demonstrate exceptional performance due to their elevated energy bandgap. This characteristic results in breakdown electric fields surpassing those found in conventional silicon electronics by more than an order of magnitude. Furthermore, the high energy bandgap offers distinctive advantages, including enhanced efficiency, drift velocity, increased voltage blocking, and high-frequency switching, making these semiconductors crucial in pushing the boundaries of electronic technology. Gallium Oxide and Silicon Carbide, distinguished by their unique properties, contribute significantly to the advancement of power electronics. Gallium Oxide, with its wide bandgap of 4.6 – 4.9 eV and excellent thermal stability, stands out for its ability to handle high electric fields and temperatures. Silicon Carbide, on the other hand, boasts a robust combination of high thermal conductivity and a wide bandgap of 3.26 eV, making it well-suited for high-power and high-temperature applications. The combination of these two materials in a heterojunction holds promise for the development of high-performance power devices. In this study, we propose a novel high breakdown voltage Silicon Carbide (SiC)/ Gallium Oxide(Ga2O3) heterojunction diode through TCAD Sentaurus. We present a comparative study of the breakdown voltage and electric field across different heterojunction lengths and under various doping concentrations. The investigated heterojunction showcases a high breakdown voltage of 1899V, making it a promising candidate for advanced power electronics applications. Furthermore, simulation results revealed a significant increase in the breakdown voltage of the SiC/Ga2O3 heterojunction, escalating from 1899 V to 4864 V when extending the heterojunction length. Improved specific ON resistance (RON, sp) and Baliga figure-of-merit (BFOM) will also be presented.

Rietveld Refinement, Structural Morphology and Magnetic Properties of La0.57Sm0.1Sr0.33−xBaxMnO3 Manganite Nanoparticles

Lanthanide-based manganite perovskites due to their possible integration both in conventional Si-based electronics, and in innovative full-oxide electronics, have led to a massive resurgence of interest. The properties and applicability of these perovskites can be tailored with the interplay of foreign ion substation, and thus lot of efforts have been made by the researchers by using various types of compound combinations. In this work, a systematic study of Ba-substituted lanthanide of a chemical formula La[Formula: see text]Sm[Formula: see text]Sr[Formula: see text]Ba[Formula: see text]MnO3 (where, [Formula: see text], 0.05, 0.1, 0.20 and 0.33) was done and the manganites were synthesized by sol–gel auto-combustion method. The structural and magnetic properties were investigated by thermogravimetric/differential thermal analysis, which was also carried out to investigate the thermal stability of the prepared samples. X-ray diffraction (XRD) patterns, transmission electron microscopy (TEM), scanning electron microscopy (SEM) etc. were employed to investigate the crystallographic structure. XRD patterns and selected area electron diffraction patterns revealed the formation of single-phase La[Formula: see text]Sm[Formula: see text]Sr[Formula: see text]Ba[Formula: see text]MnO3 perovskite materials without any signature of secondary phases. Elemental composition of the synthesized samples was investigated by the energy dispersive analysis of X-ray analysis, which confirmed the expected stoichiometry of the prepared samples. TEM and SEM observations revealed the nano-crystalline nature of the prepared samples, where particle size obtained from TEM ranges from 40[Formula: see text]nm to 70[Formula: see text]nm. It has been found that structural and magnetic properties of the parent La[Formula: see text]Sm[Formula: see text]Sr[Formula: see text]MnO3 system were greatly affected by the Ba substitution.

Theoretical analysis of magnetic, optoelectronic, and thermoelectric properties of Cs2CuCrX6 (X = Cl and Br) double perovskites for spintronic and data storage devices

Spintronics is an emerging field that has the potential to replace conventional electronics due to their comparatively high speed, low power consumption, and infinite endurance. The phenomena of ferromagnetism with high spin polarization in double perovskites make them the desired materials for spintronics. In the present work, the structure of Cs2CuCrX6 (X = Cl and Br) and their magnetic and optoelectronic properties were studied by utilizing density functional theory (DFT). For the calculations of exchange-correlation potential, PBE-sol approximation was utilized while for the accurate measurement of electronic band structure and density of states (DOS), we employed mBJ potential. Both materials exhibit cubic structure and are thermodynamically stable as confirmed by volume optimization and negative formation energy respectively. Spin-based energy-volume optimization and values of exchange constants reveal the ferromagnetic nature of materials. It has been observed that 3-d states of Cr are responsible for ferromagnetism and have the major contribution to the net magnetic moment caused by exchange splitting. Furthermore, investigations of band structure and electronic density of states showed that both Cs2CuCrCl6 and Cs2CuCrBr6 were indirect bandgap (Eg) semiconductors with the Eg values of 1.2 eV and 0.33 eV respectively. The optical spectra of materials showed strong absorption in the ultraviolet region. Lastly, the transport and thermoelectric properties (TE) of materials were investigated in the range of temperature 300 K–800 K by using the BoltzTrap code. The transport parameter which included the electrical conductivity (σ/τ) and thermal conductivity (κe/τ) of the materials showed a decreasing trend with temperature whereas the Seebeck coefficient (S) and Power factor (P.F) showed an increasing trend for Cs2CuCrCl6 while decreases in case of Cs2CuCrBr6. Furthermore, a high figure of merit (ZT) with values of 0.75 and 0.64 was obtained for Cs2CuCrCl6 and Cs2CuCrBr6 respectively. The results of this work are encouraging and show the capabilities of the discussed materials in the fields of spintronics, thermoelectric, and optoelectronics.

A reversible implantable memristor for health monitoring applications

Conventional implantable electronics based on von Neumann architectures encounter significant limitations in computing and processing vast biological information due to computational bottlenecks. The memristor with integrated memory-computing and low power consumption offer a promising solution to overcome the computational bottleneck and Moore's law limitations of traditional silicon-based implantable devices, making them the most promising candidates for next-generation implantable devices. In this work, a highly stable memristor with an Ag/BaTiO3/MnO2/FTO structure was fabricated, demonstrating retention characteristics exceeding 1200 cycles and endurance above 1000 s. The device successfully exhibited three-stage responses to biological signals after implantation in SD (Sprague-Dawley) rats. Importantly, the memristor perform remarkable reversibility, maintaining over 100 cycles of stable repetition even after extraction from the rat. This study provides a new perspective on the biomedical application of memristors, expanding the potential of implantable memristive devices in intelligent medical fields such as health monitoring and auxiliary diagnostics.

Rugged Island-Bridge Inorganic Electronics Mounted on Locally Strain-Isolated Substrates.

Various strain isolation strategies that combine rigid and stretchable regions for stretchable electronics were recently proposed, but the vulnerability of inorganic materials to mechanical stress has emerged as a major impediment to their performance. We report a strain-isolation system that combines heteropolymers with different elastic moduli (i.e., hybrid stretchable polymers) and utilize it to construct a rugged island-bridge inorganic electronics system. Two types of prepolymers were simultaneously cross-linked to form an interpenetrating polymer network at the rigid-stretchable interface, resulting in a hybrid stretchable polymer that exhibited efficient strain isolation and mechanical stability. The system, including stretchable micro-LEDs and microheaters, demonstrated consistent operation under external strain, suggesting that the rugged island-bridge inorganic electronics mounted on a locally strain-isolated substrate offer a promising solution for replacing conventional stretchable electronics, enabling devices with a variety of form factors.

Implementation of variable frequency transformer for integration of stand alone wind energy conversion system with battery energy storage

The conventional power electronics interface used for integration of wind energy conversion system (WECS) with load produces harmonics which deteriorates the quality of power supplied. To overcome this drawback, a variable frequency transformer (VFT) has been used as a link between WECS and load. For this, first a detailed steady-state modeling of VFT has been carried out. The derived model is then used for the analysis of the steady-state performance of VFT which acts as a link between WECS with battery energy storage and load for standalone operation. For this purpose, an equivalent circuit of VFT for standalone operation is developed. A set of equations for the output voltage and power delivered by VFT is derived from its equivalent circuit. The analytical solution of these equations helps in assessing the behavior of VFT. To validate the analytical results obtained from equivalent circuit, an experimental study is also carried out. The experimental study is conducted on a 3 phase, 400 V (L-L), 50 Hz, 2.2 kW, 1440 rpm, 4 pole, wound rotor induction machine. On comparison between analytical and experimental results, it is evident that both results are in good agreement. Further, the analysis is extended for variable load under various values of wind turbine generator speed and load power factor.

STRATEGI AKSELERASI DESTINASI EKOWISATA POTRE KONING DI DESA SUMBERCANTING, BONDOWOSO

This article is about the strategy to accelerate the development of the Potre Koning ecotourism destination in Sumbercanting Village, Wringin District, Bondowoso Regency which has the potential for attractive natural scenery, namely hills, teak and kedawung trees, niches in the form of paddy fields dividing the hills, siring terrace cultivation on the hillsides, waterfall, and Mustajab cave. The preparation stage including initial observation activities, mapping problems in the field, and drafting mentoring activities. Initial observations were carried out to understand the complexity and dynamics that occurred in the field. The data from initial observations was classified based on various problems, obstacles, and shortcomings faced by the Potre Koning ecotourism destination managers. In developing Potre Koning ecotourism, the management needs to pay attention to (1) management by Pokdarwis in managing the ecotourism destination; (2) management of a variety of attractions that can be developed to attract tourists; (3) spatial planning, comfort and ecotourism infrastructure, (4) promotion and marketing through conventional mass media, electronics and social media; (5) security of the ecotourism destination location, and (6) sustainability of the Potre Koning ecotourism destination. Based on the results of service in the field, it was known that the development management factor by Pokdarwis and the role of the village government, Muspika (District Head, Danramil, Kapolsek) were key factors in the success of destination development. Potre Koning ecotourism's development was expected to positively impact local economic growth in Sumbercanting Village, increasing the number of tourists, preserving ecotourism objects, and maximum community participation.

E-Tattoos: Toward Functional but Imperceptible Interfacing with Human Skin.

The human body continuously emits physiological and psychological information from head to toe. Wearable electronics capable of noninvasively and accurately digitizing this information without compromising user comfort or mobility have the potential to revolutionize telemedicine, mobile health, and both human-machine or human-metaverse interactions. However, state-of-the-art wearable electronics face limitations regarding wearability and functionality due to the mechanical incompatibility between conventional rigid, planar electronics and soft, curvy human skin surfaces. E-Tattoos, a unique type of wearable electronics, are defined by their ultrathin and skin-soft characteristics, which enable noninvasive and comfortable lamination on human skin surfaces without causing obstruction or even mechanical perception. This review article offers an exhaustive exploration of e-tattoos, accounting for their materials, structures, manufacturing processes, properties, functionalities, applications, and remaining challenges. We begin by summarizing the properties of human skin and their effects on signal transmission across the e-tattoo-skin interface. Following this is a discussion of the materials, structural designs, manufacturing, and skin attachment processes of e-tattoos. We classify e-tattoo functionalities into electrical, mechanical, optical, thermal, and chemical sensing, as well as wound healing and other treatments. After discussing energy harvesting and storage capabilities, we outline strategies for the system integration of wireless e-tattoos. In the end, we offer personal perspectives on the remaining challenges and future opportunities in the field.

Design, Fabrication, and Characterization of a 4H-SiC CMOS Readout Circuit for Monolithic Integration with SiC Sensors

This paper reports the design and fabrication of a 4H-SiC CMOS readout circuit enabling monolithic integration of silicon carbide (SiC) sensors and circuits. Compared to conventional Si electronics, 4H-SiC integrated circuits can sustain operation in harsh conditions such as higher temperatures and radiation levels. The proposed amplifier performance is well balanced through the temperature range of 25C to 400C. Compared to state-of-the-art, the proposed SiC readout circuit does not include any off-chip components. The amplifier is fully differential, and hence shows improved common-mode rejection and signal-to-noise ratio (SNR). It can be monolithically integrated with SiC sensors in a scalable SiC technology.

High-density superconductive logic circuits utilizing 0 and π josephson junctions

Superconductor Electronics (SCE) is a fast and power-efficient technology with great potential for overcoming conventional CMOS electronics’ scaling limits. Nevertheless, the primary challenge confronting SCE today is its integration level, which lags several orders of magnitude behind CMOS circuits. In this study, we have innovated and simulated a novel logic family grounded in the principles of phase shifts occurring in 0 and π Josephson junctions. The fast phase logic (FPL) eliminates the need for large inductor loops and shunt resistances by combining the half-flux and phase logic. Therefore, the Josephson junction (JJ) area only limits the integration density. The cells designed with this paradigm are fast, and the clock-to-Q delay for logic cells is about 4ps. While maintaining over 50% parameter margins for wiring cells. This logic is power efficient and can increase the integration by at least 100×in the SCE chips.

Voltage-Controlled Magnon Transistor via Tuning Interfacial Exchange Coupling.

Magnon transistors that can effectively regulate magnon transport by an electric field are desired for magnonics, which aims to provide a Joule-heating free alternative to the conventional electronics owing to the electric neutrality of magnons (the key carriers of spin-angular momenta in the magnonics). However, also due to their electric neutrality, magnons have no access to directly interact with an electric field and it is thus difficult to manipulate magnon transport by voltages straightforwardly. Here, we demonstrated a gate voltage (V_{g}) applied on a nonmagnetic metal and magnetic insulator (MI) interface that bent the energy band of the MI and then modulated the probability for conduction electrons in the nonmagnetic metal to tunnel into the MI, which can consequently enhance or weaken the spin-magnon conversion efficiency at the interface. A voltage-controlled magnon transistor based on the magnon-mediated electric current drag (MECD) effect in a Pt-Y_{3}Fe_{5}O_{12}-Pt sandwich was then experimentally realized with V_{g} modulating the magnitude of the MECD signal. The obtained efficiency (the change ratio between the MECD voltage at ±V_{g}) reached 10%/(MV/cm) at 300K. This prototype of magnon transistor offers an effective scheme to control magnon transport by a gate voltage.

A new scheme of all-optical 2:1 multiplexer (MUX) and MUX-based combinational circuits using nonlinear kerr-type materials

Optoelectronics, often known as photon-based electronics, is well recognised for being more effective than conventional electronics for communication. To create a superfast computer, several devices have previously been developed in the field of all optical computing systems. Here, we have put forth an all-optical 2:1 multiplexer with the usage of nonlinear material exhibiting a strong ac Kerr effect and 2:1 Multiplexer (MUX) based all optical -photonic switches - NOT, OR, AND, NAND, NOR etc The sole method for building combinational logic circuits is to utilise MUX. This work is made simpler by the Shannon decomposition theorem than by other approaches. In this study, input and output are expressed as the presence of a light signal with a prefixed intensity as binary 1 and the absence of a light signal as binary 0 using an intensity-based all-optical device and positive logic. Since the system is entirely optical, our current design enables very-high speed (terahertz) computation, which is not possible with typical semiconductor electronic switches. Validation through mathematical computations-based PYTHON simulations establishes the efficacy of the proposed approach. This research holds promise for applications in industrial and commercial contexts, offering enhanced performance and versatility.

In-Plane Anisotropy in the Layered Topological Insulator Ta2Ni3Te5 Investigated via TEM and Polarized Raman Spectroscopy.

Layered Ta2M3Te5 (M = Pd, Ni) has emerged as a platform to study 2D topological insulators, which have exotic properties such as spin-momentum locking and the presence of Dirac fermions for use in conventional and quantum-based electronics. In particular, Ta2Ni3Te5 has been shown to have superconductivity under pressure and is predicted to have second-order topology. Despite being an interesting material with fascinating physics, the detailed crystalline and phononic properties of this material are still unknown. In this study, we use transmission electron microscopy (TEM) and polarized Raman spectroscopy (PRS) to reveal the anisotropic properties of exfoliated few-layer Ta2Ni3Te5. An electron diffraction and TEM study reveals structural anisotropy in the material, with a preferential crystal orientation along the [010] direction. Through Raman spectroscopy, we discovered 15 vibrational modes, 3 of which are ultralow-frequency modes, which show anisotropic response with sample orientation varying with the polarization of the incident beam. Using angle-resolved PRS, we assigned the vibrational symmetries of 11 modes to Ag and two modes to B3g. We also found that linear dichroism plays a role in understanding the Raman signature of this material, which requires the use of complex elements in the Raman tensors. The anisotropy of the Raman scattering also depends on the excitation energies. Our observations reveal the anisotropic nature of Ta2Ni3Te5, establish a quick and nondestructive Raman fingerprint for determining sample orientation, and represent a significant advance in the fundamental understanding of the two-dimensional topological insulator (2DTI) Ta2Ni3Te5 material.

Application of nanogenerators in acoustics based on artificial intelligence and machine learning

As artificial intelligence (AI) advances, it is critical to give conventional electronics the capacity to “think,” “analyze,” and “advise.” The need for intelligent, self-powered devices has increased due to recent significant developments in the computer field, namely, in the fields of AI and machine learning (ML). The use of nanogenerators in the area of acoustics is examined in this Review, with an emphasis on how they might be integrated with ML and AI. Innovative energy-harvesting devices called nanogenerators are able to produce electrical power from outside sources, such as vibrations in the air or mechanical movements. The study examines a number of acoustic applications for nanogenerators, such as energy harvesting, sound detection, noise monitoring, and acoustic sensing. Furthermore, the research highlights how AI and ML techniques enhance the performance of nanogenerators and enable more efficient acoustic applications through data analysis and model training. At the end of this Review, the future development prospects of nanogenerators based on AI and ML were discussed.

Can tunneling current in molecular junctions be so strongly temperature dependent to challenge a hopping mechanism? Analytical formulas answer this question and provide important insight into large area junctions.

Analytical equations like Richardson-Dushman's or Shockley's provided a general, if simplified conceptual background, which was widely accepted in conventional electronics and made a fundamental contribution to advances in the field. In the attempt to develop a (highly desirable, but so far missing) counterpart for molecular electronics, in this work, we deduce a general analytical formula for the tunneling current through molecular junctions mediated by a single level that is valid for any bias voltage and temperature. Starting from this expression, which is exact and obviates cumbersome numerical integration, in the low and high temperature limits we also provide analytical formulas expressing the current in terms of elementary functions. They are accurate for broad model parameter ranges relevant for real molecular junctions. Within this theoretical framework we show that: (i) by varying the temperature, the tunneling current can vary by several orders of magnitude, thus debunking the myth that a strong temperature dependence of the current is evidence for a hopping mechanism, (ii) real molecular junctions can undergo a gradual (Sommerfeld-Arrhenius) transition from a weakly temperature dependent to a strongly ("exponential") temperature dependent current that can be tuned by the applied bias, and (iii) important insight into large area molecular junctions with eutectic gallium indium alloy (EGaIn) top electrodes can be gained. E.g., merely based on transport data, we estimate that the current carrying molecules represent only a fraction of f ≈ 4 × 10-4 out of the total number of molecules in a large area Au-S-(CH2)13-CH3/EGaIn junction.

(Invited) Direct Ink Writing of Supercapacitors for Flexible and Wearable Applications

Direct Ink Writing (DIW) has recently emerged as a revolutionizing 3D printing technology for automated, cost-effective, and smart manufacturing of flexible and wearable electronic devices. Due to huge potential of flexible and wearable electronic devices in healthcare, sports, portable electronics, aircraft structures, robotics, etc., it is imperative to find the reliable and cost-effective methods to shift conventional rigid electronics to flexible/ wearable electronics. DIW process is highly efficient to fabricate high performance supercapacitors due to its processing capability to print wide range of materials and its simplicity. This work is focused on the fabrication of silicon and graphene-based supercapacitors using DIW and their application for flexible, stretchable, and wearable electronics. Different critical parameters for DIW such as rheology requirements of inks, material selection for electrode/ electrolyte, surface requirements to ensure better adhesion between printing layers, mechanical/ material testing of fabricated devices, and their electrochemical performance have been discussed to get a reliable energy storage device.

(Invited) Advanced Design Concepts for Vertical Gallium Nitride MOSFETs

Wide-bandgap semiconductors have a significant advantage over conventional Si-based electronics by leveraging materials properties to achieve higher breakdown voltage, lower on-resistance, and high-frequency operation. Gallium nitride (GaN) is of interest for vertical device architectures but directly competes with the already established silicon carbide (SiC) power devices. In the case of vertical GaN rectifiers which are unipolar figure-of-merit limited, the materials advantage of GaN provides a modest gain in terms of critical electric field and very slight gains in bulk mobility and saturation velocity, while being at a disadvantage in terms of thermal conductivity compared to SiC. However, despite still being a very immature technology, vertical GaN MOSFETs have demonstrated channel mobilities upwards of 200 cm2/V·s, over three times that of SiC-based MOSFETs. For 1200V-class devices, channel mobility directly contributes to a significant portion of device on-resistance, and it is therefore expected that vertical GaN MOSFETs would offer a substantial performance advantage compared to SiC MOSFETs. Despite this, the development of vertical GaN devices that demonstrate this theoretical potential faces many challenges. Several fundamental limitations exist within the manufacturing process that prohibit GaN devices from directly mirroring the design rules for similar SiC devices. In this talk, we will discuss several key design concepts recently developed for vertical GaN MOSFETs which serve to address several critical issues for GaN.Limitations in selective-area doping for GaN provide an additional challenge in designing edge termination structures, advanced features that protect the gate dielectric during the blocking state, and provides restrictions on minimizing cell pitch. Proper edge termination design is required to reach an avalanche voltage near the theoretical limit and avoid early breakdown. We present an optimized design point for the edge termination with a good match between theoretical and experimental data using a step-etched junction termination extension. Despite a well-designed edge termination, early breakdown will occur in the gate dielectric at the bottom of the gate trench due to field crowding in the dielectric at high blocking voltages. We propose a new method for protecting the gate dielectric by means of a buried field shield formed by an etch-and-regrowth process. Experimental data shows this gate dielectric failure can occur as early as 1/3rd of the designed blocking voltage. The field shield design is shown in simulation to sufficiently reduce the electric field in the gate dielectric to below 4 MV/cm with minimal or no derating of the device depending on geometry of the shield. Additional methods will be presented on new techniques to minimize cell pitch, a critical factor necessary to compete against SiC. Cell pitch minimization not only reduces on-resistance and gate-charge trade-offs, but it is also a driving factor to reduce cost and increase die density on wafer. Finally, techniques have been developed for advanced metal contact designs specific to the trench MOSFET, which further aid in reducing cell pitch. This work was supported by the Electric Drivetrain Consortium managed by Susan Rogers of DOE’s Vehicle Technologies Office. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. This paper describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the U.S. Department of Energy or the United States Government.

Influence of SrTiO3/Fe2O3 nano-fillers assisted PVDF-HFP polymer nanocomposite films on dielectric, impedance, and conductivity studies for energy storage applications

abstract In recent years, electronic devices with trendy flexibility and compatibility have become the competitive alternative to conventional electronics. In the present work, flexible polymer nanocomposite films composed of poly(vinylidene fluoride-co-hexafluoropropylene), iron oxide, and strontium titanate (PVDF-HFP/SrTiO3/Fe2O3) were synthesized by the solution-casting method. The formation and structural features of this composite material have been analyzed by X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Thermogravimetric (TGA), and SEM. SEM results confirm the homogeneous dispersion of SrTiO3 and Fe2O3 within the host polymer. The uniform dispersion of the embedded metal species enhances the dielectric values up to 462 on optimization with infused rigidity. The impedance studies of PVDF-HFP/SrTiO3/Fe2O3 were performed in the temperature region of 50–150 °C at various frequencies ranging from 50 Hz to 10 MHz and the AC conductivity studies suggested that synthesized polymer nanocomposite shows higher conductivity with the maximum conductivity value was 8.20 × 10−3S/m. Polymer nanocomposite films with large dielectric constant and minimum dielectric loss are highly recommendable for flexible energy storage applications. Also, rapid development of novel material for flexible electronics is in great demand, which suggests it is an alternate source for future energy storage application.