Versatile Papertronics: Photo-Induced Synapse and Security Applications on Papers.

Paper is a readily available material in nature. Its recyclability, eco-friendliness, portability, flexibility, and affordability make it a favored substrate for researchers seeking cost-effective solutions. Electronic devices based on solution process are fabricated on paper and banknotes using PVK and SnO2 nanoparticles. The devices manufactured on paper substrates exhibit photosynaptic behavior under ultraviolet pulse illumination, stemming from numerous interactions on the surface of the SnO2 nanoparticles. A light-modulated artificial synapse device is realized on a paper at a low voltage bias of -0.01 V, with an average recognition rate of 91.7% based on the Yale Face Database. As a security device on a banknote, 400 devices in a 20 × 20 array configuration exhibited random electrical characteristics owing to the local morphology of the SnO2 nanoparticles and differences in the depletion layer width at the SnO2/PVK interface. The security Physically Unclonable Functions (PUF) key based on the current distribution extracted at -1 V show unpredictable reproducibility with 50% uniformity, 48.7% inter-Hamming distance, and 50.1% bit-aliasing rates. Moreover, the device maintained its properties for more than 210 days under a curvature radius of 8.75 mm and bias and UV irradiation stress conditions.

Overcoming Downscaling Limitations in Organic Semiconductors: Strategies and Progress.

Organic semiconductors have great potential to revolutionize electronics by enabling flexible and eco-friendly manufacturing of electronic devices on plastic film substrates. Recent research and development led to the creation of printed displays, radio-frequency identification tags, smart labels, and sensors based on organic electronics. Over the last 3 decades, significant progress has been made in realizing electronic devices with unprecedented features, such as wearable sensors, disposable electronics, and foldable displays, through the exploitation of desirable characteristics in organic electronics. Neverthless, the down-scalability of organic electronic devices remains a crucial consideration. To address this, efforts are extensively explored. It is of utmost importance to further develop these alternative patterning methods to overcome the downscaling challenge. This review comprehensively discusses the efforts and strategies aimed at overcoming the limitations of downscaling in organic semiconductors, with a particular focus on four main areas: 1) lithography-compatible organic semiconductors, 2) fine patterning of printing methods, 3) organic material deposition on pre-fabricated devices, and 4) vertical-channeled organic electronics. By discussing these areas, the full potential of organic semiconductors can be unlocked, and the field of flexible and sustainable electronics can be advanced.

Superb Li-Ion Storage of Sn-Based Anode Assisted by Conductive Hybrid Buffering Matrix.

Although Sn has been intensively studied as one of the most promising anode materials to replace commercialized graphite, its cycling and rate performances are still unsatisfactory owing to the insufficient control of its large volume change during cycling and poor electrochemical kinetics. Herein, we propose a Sn-TiO2-C ternary composite as a promising anode material to overcome these limitations. The hybrid TiO2-C matrix synthesized via two-step high-energy ball milling effectively regulated the irreversible lithiation/delithiation of the active Sn electrode and facilitated Li-ion diffusion. At the appropriate C concentration, Sn-TiO2-C exhibited significantly enhanced cycling performance and rate capability compared with its counterparts (Sn-TiO2 and Sn-C). Sn-TiO2-C delivers good reversible specific capacities (669 mAh g-1 after 100 cycles at 200 mA g-1 and 651 mAh g-1 after 500 cycles at 500 mA g-1) and rate performance (446 mAh g-1 at 3000 mA g-1). The superiority of Sn-TiO2-C over Sn-TiO2 and Sn-C was corroborated with electrochemical impedance spectroscopy, which revealed faster Li-ion diffusion kinetics in the presence of the hybrid TiO2-C matrix than in the presence of TiO2 or C alone. Therefore, Sn-TiO2-C is a potential anode for next-generation Li-ion batteries.

Electron-rich hybrid matrix to enhance molybdenum oxide-based anode performance for Lithium-Ion batteries.

Although MoO2-based electrodes have been intensively studied as potential candidate anodes for lithium-ion batteries (LIBs) based on their high theoretical capacity (840 mAh g-1 and 5447 mAh cm-3), common issues such as severe volume variation, electrical conductivity loss, and low ionic conductivity, are prevalent. In this study, we demonstrate enhanced Li-ion kinetics and electrical conductivity of MoO2-based anodes with ternary MoO2-Cu-C composite materials. The MoO2-Cu-C was synthesized via two-step high energy ball milling where Mo and CuO are milled, followed by the secondary milling with C. With the introduction of the Cu-C hybrid matrix in MoO2 nanoparticles via the element transfer method using mechanochemical reactions, the sluggish Li-ion diffusion and unstable cycling behavior were significantly improved. The inactive Cu-C matrix contributes to the increase in electrical and ionic conductivity and mechanical stability of active MoO2 during cycling, as characterized by various electrochemical analyses and ex situ analysis techniques. Hence, the MoO2-Cu-C anode delivered promising cycling performance (674 mAh g-1 (at 0.1 A g-1) and 520 mAh g-1 (at 0.5 A g-1), respectively, after 100 cycles) and high-rate property (73% retention at 5 A g-1 as comparison with the specific capacity at 0.1 A g-1). The MoO2-Cu-C electrode is a propitious next-generation anode for LIBs.

Gallium-Telluride-Based Composite as Promising Lithium Storage Material.

Various applications of gallium telluride have been investigated, such as in optoelectronic devices, radiation detectors, solar cells, and semiconductors, owing to its unique electronic, mechanical, and structural properties. Among the various forms of gallium telluride (e.g., GaTe, Ga3Te4, Ga2Te3, and Ga2Te5), we propose a gallium (III) telluride (Ga2Te3)-based composite (Ga2Te3-TiO2-C) as a prospective anode for Li-ion batteries (LIBs). The lithiation/delithiation phase change mechanism of Ga2Te3 was examined. The existence of the TiO2-C hybrid buffering matrix improved the electrical conductivity as well as mechanical integrity of the composite anode for LIBs. Furthermore, the impact of the C concentration on the performance of Ga2Te3-TiO2-C was comprehensively studied through cyclic voltammetry, differential capacity analysis, and electrochemical impedance spectroscopy. The Ga2Te3-TiO2-C electrode showed high rate capability (capacity retention of 96% at 10 A g-1 relative to 0.1 A g-1) as well as high reversible specific capacity (769 mAh g-1 after 300 cycles at 100 mA g-1). The capacity of Ga2Te3-TiO2-C was enhanced by the synergistic interaction of TiO2 and amorphous C. It thereby outperformed the majority of the most recent Ga-based LIB electrodes. Thus, Ga2Te3-TiO2-C can be thought of as a prospective anode for LIBs in the future.

Ga2Te3-Based Composite Anodes for High-Performance Sodium-Ion Batteries.

Recently, metal chalcogenides have received considerable attention as prospective anode materials for sodium-ion batteries (SIBs) because of their high theoretical capacities based on their alloying or conversion reactions. Herein, we demonstrate a gallium(III) telluride (Ga2Te3)-based ternary composite (Ga2Te3-TiO2-C) synthesized via a simple high-energy ball mill as a great candidate SIB anode material for the first time. The electrochemical performance, as well as the phase transition mechanism of Ga2Te3 during sodiation/desodiation, is investigated. Furthermore, the effect of C content on the performance of Ga2Te3-TiO2-C is studied using various electrochemical analyses. As a result, Ga2Te3-TiO2-C with an optimum carbon content of 10% (Ga2Te3-TiO2-C(10%)) exhibited a specific capacity of 437 mAh·g-1 after 300 cycles at 100 mA·g-1 and a high-rate capability (capacity retention of 96% at 10 A·g-1 relative to 0.1 A·g-1). The good electrochemical properties of Ga2Te3-TiO2-C(10%) benefited from the presence of the TiO2-C hybrid buffering matrix, which improved the mechanical integrity and electrical conductivity of the electrode. This research opens a new direction for the improvement of high-performance advanced SIB anodes with a simple synthesis process.

Nanomaterials for Ion Battery Applications.

Nanomaterials offer opportunities to improve battery performance in terms of energy density and electrochemical reaction kinetics owing to a significant increase in the effective surface area of electrodes and reduced ion diffusion pathways [...].

The Effects of the Binder and Buffering Matrix on InSb-Based Anodes for High-Performance Rechargeable Li-Ion Batteries.

C-decorated intermetallic InSb (InSb-C) was developed as a novel high-performance anode material for lithium-ion batteries (LIBs). InSb nanoparticles synthesized via a mechanochemical reaction were characterized using X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray spectroscopy (EDX). The effects of the binder and buffering matrix on the active InSb were investigated. Poly(acrylic acid) (PAA) was found to significantly improve the cycling stability owing to its strong hydrogen bonding. The addition of amorphous C to InSb further enhanced mechanical stability and electronic conductivity. As a result, InSb-C demonstrated good electrochemical Li-ion storage performance: a high reversible specific capacity (878 mAh·g-1 at 100 mA·g-1 after 140 cycles) and good rate capability (capacity retention of 98% at 10 A·g-1 as compared to 0.1 A·g-1). The effects of PAA and C were comprehensively studied using cyclic voltammetry, differential capacity plots, ex-situ SEM, and electrochemical impedance spectroscopy (EIS). In addition, the electrochemical reaction mechanism of InSb was revealed using ex-situ XRD. InSb-C exhibited a better performance than many recently reported Sb-based electrodes; thus, it can be considered as a potential anode material in LIBs.

Zn Metal Anodes for Zn-Ion Batteries in Mild Aqueous Electrolytes: Challenges and Strategies.

Over the past few years, rechargeable aqueous Zn-ion batteries have garnered significant interest as potential alternatives for lithium-ion batteries because of their low cost, high theoretical capacity, low redox potential, and environmentally friendliness. However, several constraints associated with Zn metal anodes, such as the growth of Zn dendrites, occurrence of side reactions, and hydrogen evolution during repeated stripping/plating processes result in poor cycling life and low Coulombic efficiency, which severely impede further advancements in this technology. Despite recent efforts and impressive breakthroughs, the origin of these fundamental obstacles remains unclear and no successful strategy that can address these issues has been developed yet to realize the practical applications of rechargeable aqueous Zn-ion batteries. In this review, we have discussed various issues associated with the use of Zn metal anodes in mildly acidic aqueous electrolytes. Various strategies, including the shielding of the Zn surface, regulating the Zn deposition behavior, creating a uniform electric field, and controlling the surface energy of Zn metal anodes to repress the growth of Zn dendrites and the occurrence of side reactions, proposed to overcome the limitations of Zn metal anodes have also been discussed. Finally, the future perspectives of Zn anodes and possible design strategies for developing highly stable Zn anodes in mildly acidic aqueous environments have been discussed.

Synthesis of Lead-Free CaTiO3 Oxide Perovskite Film through Solution Combustion Method and Its Thickness-Dependent Hysteresis Behaviors within 100 mV Operation.

Perovskite is attracting considerable interest because of its excellent semiconducting properties and optoelectronic performance. In particular, lead perovskites have been used extensively in photovoltaic, photodetectors, thin-film transistors, and various electronic applications. On the other hand, the elimination of lead is essential because of its strong toxicity. This paper reports the synthesis of lead-free calcium titanate perovskite (CaTiO3) using a solution-processed combustion method. The chemical and morphological properties of CaTiO3 were examined as a function of its thickness by scanning electron microscopy, X-ray diffraction (XRD), atomic force microscopy, X-ray photoelectron spectroscopy, and ultraviolet-visible spectrophotometry. The analysis showed that thicker films formed by a cumulative coating result in larger grains and more oxygen vacancies. Furthermore, thickness-dependent hysteresis behaviors were examined by fabricating a metal-CaTiO3-metal structure. The electrical hysteresis could be controlled over an extremely low voltage operation, as low as 100 mV, by varying the grain size and oxygen vacancies.

Review of ZnO Binary and Ternary Composite Anodes for Lithium-Ion Batteries.

To enhance the performance of lithium-ion batteries, zinc oxide (ZnO) has generated interest as an anode candidate owing to its high theoretical capacity. However, because of its limitations such as its slow chemical reaction kinetics, intense capacity fading on potential cycling, and low rate capability, composite anodes of ZnO and other materials are manufactured. In this study, we introduce binary and ternary composites of ZnO with other metal oxides (MOs) and carbon-based materials. Most ZnO-based composite anodes exhibit a higher specific capacity, rate performance, and cycling stability than a single ZnO anode. The synergistic effects between ZnO and the other MOs or carbon-based materials can explain the superior electrochemical characteristics of these ZnO-based composites. This review also discusses some of their current limitations.

Recent Advances in Transition Metal Dichalcogenide Cathode Materials for Aqueous Rechargeable Multivalent Metal-Ion Batteries.

The generation of renewable energy is a promising solution to counter the rapid increase in energy consumption. Nevertheless, the availability of renewable resources (e.g., wind, solar, and tidal) is non-continuous and temporary in nature, posing new demands for the production of next-generation large-scale energy storage devices. Because of their low cost, highly abundant raw materials, high safety, and environmental friendliness, aqueous rechargeable multivalent metal-ion batteries (AMMIBs) have recently garnered immense attention. However, several challenges hamper the development of AMMIBs, including their narrow electrochemical stability, poor ion diffusion kinetics, and electrode instability. Transition metal dichalcogenides (TMDs) have been extensively investigated for applications in energy storage devices because of their distinct chemical and physical properties. The wide interlayer distance of layered TMDs is an appealing property for ion diffusion and intercalation. This review focuses on the most recent advances in TMDs as cathode materials for aqueous rechargeable batteries based on multivalent charge carriers (Zn2+, Mg2+, and Al3+). Through this review, the key aspects of TMD materials for high-performance AMMIBs are highlighted. Furthermore, additional suggestions and strategies for the development of improved TMDs are discussed to inspire new research directions.

Self-Powered Low-Cost UVC Sensor Based on Organic-Inorganic Heterojunction for Partial Discharge Detection.

Power outages caused by the aging of high-voltage power facilities can cause significant economic and social damage. To prevent such problems, it is necessary to implement a widespread and sustainable monitoring system. Partial discharge (PD) is a preliminary symptom of power equipment aging accompanying the light, typically in the UV range. UVC (200-280 nm) is more useful than UVA and UVB because of low interference from the environment owing to its solar-blindness by the stratosphere. Therefore, to realize a wide-range and durable diagnosis system, it is necessary to develop sensors that can selectively detect UVC, while enabling mass production at low-cost and low power consumption. Here, a solution-processable photodiode sensor that is inexpensive, mass-producible, and self-powered with selective UVC detection is developed. The optoelectronic characteristics of photodiode consisting of organic p-polymer and inorganic n-ZnO nanoparticles are systematically studied to determine the optimum p-type polymer and its thickness. The device shows high-performance: fast response time (rise/fall time: 36.6/37.0 ms) and high spectral response in the UVC region (maximum responsivity of 20 mA W-1 ) under self-powered operation. Furthermore, the practical application of the device to detect PD signals with a visual alarm system under UVC release conditions is demonstrated.

Room Temperature Operation of UV Photocatalytic Functionalized AlGaN/GaN Heterostructure Hydrogen Sensor.

An AlGaN/GaN heterostructure based hydrogen sensor was fabricated using a dual catalyst layer with ZnO-nanoparticles (NPs) atop of Pd catalyst film. The ZnO-NPs were synthesized to have an average diameter of ~10 nm and spin coated on the Pd catalyst layer. Unlike the conventional catalytic reaction, the fabricated sensors exhibited room temperature operation without heating owing to the photocatalytic reaction of the ZnO-NPs with ultraviolet illumination at 280 nm. A sensing response of 25% was achieved for a hydrogen concentration of 4% at room temperature with fast response and recovery times; a response time of 8 s and a recovery time of 11 s.

Inorganic Fillers in Composite Gel Polymer Electrolytes for High-Performance Lithium and Non-Lithium Polymer Batteries.

Among the various types of polymer electrolytes, gel polymer electrolytes have been considered as promising electrolytes for high-performance lithium and non-lithium batteries. The introduction of inorganic fillers into the polymer-salt system of gel polymer electrolytes has emerged as an effective strategy to achieve high ionic conductivity and excellent interfacial contact with the electrode. In this review, the detailed roles of inorganic fillers in composite gel polymer electrolytes are presented based on their physical and electrochemical properties in lithium and non-lithium polymer batteries. First, we summarize the historical developments of gel polymer electrolytes. Then, a list of detailed fillers applied in gel polymer electrolytes is presented. Possible mechanisms of conductivity enhancement by the addition of inorganic fillers are discussed for each inorganic filler. Subsequently, inorganic filler/polymer composite electrolytes studied for use in various battery systems, including Li-, Na-, Mg-, and Zn-ion batteries, are discussed. Finally, the future perspectives and requirements of the current composite gel polymer electrolyte technologies are highlighted.

Zinc Telluride as Electrochemical Storage Material for High-Performance Sodium-Ion Batteries.

High-energy ball milling (HEBM) is used to synthesize zinc telluride (ZnTe) and amorphous C (ZnTe-C) nanocomposites as novel anode materials for sodium-ion batteries (SIBs). A nanostruc-tured ZnTe-C composite is prepared using Zn, Te, and acetylene black as precursor materials via a facile two-step HEBM process. The initial HEBM of Zn and Te induces the formation of the ZnTe alloy nanostructure via a mechanochemical reaction. The subsequent HEBM process generates the ZnTe composite embedded in amorphous C (ZnTe-C), as confirmed using X-ray diffraction, transmission electron microscopy, and element mapping analyses. When used as SIB anode, the ZnTe-C composite exhibits good cyclic life (specific discharge capacities of 383 mAh g-1 at 0.1 A g-1 over 150 cycles and 373 mAh g-1 at 0.5 A g-1 after 500 cycles) and excellent rate capability (89% capacity retention at 10 A g-1 relative to that at 0.1 A g-1). The impedance analysis and ex situ scanning electron microscopy results reveal that the properties of ZnTe-C are superior to those of ZnTe because C serves as buffering matrix that suppresses the volume changes in ZnTe during alloying/dealloying and reduces the charge transfer resistance. The ZnTe-C nanocomposite in this study is a promising candidate for high-performance SIB anodes.

GaP-TiO2-C Nanocomposite as High-Performance Sodium-Ion Batteries Anode.

GaP-TiO2-C composites with three different C concentrations are synthesized via a high-energy mechanical milling. The analysis of the structural characteristics of GaP-TiO2-C using X-ray diffraction and high-resolution transmission electron microscopy reveals that the nanosized GaP and TiO2 crystallites are uniformly distributed in the amorphous C matrix. The GaP-TiO2-C(20%) composite exhibits a high Na storage capacity of 266 mAh g-1 at the current density of 0.1 A g-1 after 100 cycles, and the remarkable rate capability of 224 mAh g-1 even at the higher current density of 10 A g-1. In addition, the GaP-TiO2-C(20%) composite presents great cycling performance and the capacity of 213 mAh g-1 at the current density of 0.5 A g-1 after 300 cycles. The outstanding cycling performance and rate capability of GaP-TiO2-C(20%) anode can be attributed to the favorable morphology of GaP-TiO2-C composite that accommodates large volume changes during cycling.

A Study on the Characteristics of Perovskite/ZnO-Based Ultraviolet Sensors.

In this study, a UVC sensor was implemented using CH3NH3PbI3, a perovskite material. The UV sensor made with a p-i-n structure uses PEDOT:PSS as the p-type material and ZnO as the n-type material. The fabricated device shows a responsivity of 1.60 mA/W and a detectivity of 2.25×1010 Jones under 254 nm illumination with a power density of 1.02 mW/cm² at 2 V. In addition, the manufactured UV sensor is a self-powered perovskite-based UV sensor that can operate without external bias. Therefore, this UVC sensor can have applications in various fields.

Development of Antimicrobial CuO/(3-aminopropyl)Triethoxysilane Activated Carbon Fiber.

CuO nanoparticles (NPs) have been used for the antimicrobial agent against different pathogenic microorganisms. In this study, CuO NPs are immobilized on the surface of activated carbon fiber (ACF) with the enhancement of (3-aminopropyl)triethoxysilane (APTES) as an organic binder. The obtained fibers are evaluated by coating efficiency, structural deformation, and antimicrobial activities. In the results, APTES can improve the immobilization of CuO on the surface of ACF. Also, the curing of silane layers at high temperature leads to the high coating efficiencies as well as structural reinforcement. The samples with drying step after APTES coating step (denoted as DA-CuO) have the highest antimicrobial activity against both Escherichia coli and Staphylococcus aureus after 24 hours treatment, respectively.

Wide-Bandgap CaSnO3 Perovskite As an Efficient and Selective Deep-UV Absorber for Self-Powered and High-Performance p-i-n Photodetector.

Calcium stannate (CaSnO3) is an inorganic perovskite material with an ultrawide bandgap (4.2-4.4 eV) that is associated with its unique structural characteristics. Owing to its remarkable optical and electric properties and high physical and chemical stability, it has recently drawn significant interest for various applications such as photocatalysts for the degradation of organic compounds and hydrogen production under UV radiation, gas sensors, and thermally stable capacitors. In this study, we demonstrate a self-powered deep-UV (DUV) p-i-n photodetector consisting of CaSnO3 thin film as an efficient DUV absorber via a low-temperature solution process. The physical, optical, and electrical properties of the as-synthesized CaSnO3 are characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy, ultraviolet-visible spectroscopy, photoluminescence spectroscopy, space charge limited current, and four-point probe measurements. As a key component in a p-i-n DUV photodetector, the thickness of the CaSnO3 absorber layer and operating bias are optimized to enhance charge carrier transport, light absorption, and signal-to-noise ratio. As a result, the optimized device shows a high performance at zero bias under 254 nm UV illumination: with a specific detectivity of 1.56 × 1010 Jones, fast rise/fall time of 80/70 ms, and high 254:365 nm photocurrent rejection ratio of 5.5 along with a stable photoresponse during 100 continuous cycles initially as well as after 1 month of storage. Accordingly, this study suggests that a novel CaSnO3-based photodiode prepared via a solution process can be employed for many practical DUV-detection applications.