Conductive inks are essential for developing flexible and wearable electronic devices, where printability and electrical performance must be finely balanced. However, achieving high conductivity while minimizing costly silver filler content remains a key challenge in ink formulation. In this work, we demonstrate that a simple ball-milling process transforms spherical silver particles into platelet-shaped fillers, dramatically enhancing conductivity at equivalent filler loading. The resulting inks show a reduction in sheet resistance from ~180 Ω/□ to ~ 0.57 Ω/□ at 70 wt% filler content, with improved performance attributed to surface-to-surface contact between platelets. Moreover, we show that filler content influences not only electrical conductivity but also ink viscosity, with the 53.8 wt% formulation achieving a practical balance between conductivity, processability, and cost. This morphology- and composition-controlled ink design offers a scalable strategy for manufacturing high-performance, cost-effective conductive inks suitable for next-generation printed electronics.

The growing demand for miniaturized, lightweight, and sustainable electronic devices has intensified the need for advanced bonding materials. Existing electrically conductive adhesives (ECAs) often rely on high silver (Ag) content, resulting in elevated costs and environmental concerns. This study successfully developed a novel ECA with significantly reduced Ag content without compromising essential electrical conductivity and adhesion performance. Experimental results revealed that the optimized ECA demonstrates electrical conductivity comparable to that of commercial products, with notable advantages in cost reduction and eco-friendliness. These advancements position the developed ECA as a promising solution for next-generation electronic manufacturing, contributing to low-carbon technologies and sustainable practices. Future applications could further broaden its use across diverse electronic systems, driving progress in environmentally conscious technologies.

Lithium-ion batteries are widely used in various applications, including electric vehicles and portable electronics, due to their high energy density and long cycle life. The performance of lithium-ion batteries can be improved by using solid electrolytes, in terms of higher safety, stability, and energy density. Li_1.5Al_0.5Ti_1.5(PO₄)₃ (LATP) is a promising solid electrolyte for all-solid-state lithium batteries due to its high ionic conductivity and excellent stability. However, the ionic conductivity of LATP needs to be improved for commercializing all-solid-state lithium battery systems. In this study, we investigate the microstructures and ionic conductivities of LATP by incorporating B₂O₃ glass ceramics. The smaller grain size and narrow size distribution were obtained after the introduction of B₂O₃ in LATP, which is attributed to the B₂O₃ glass on grain boundaries of LATP. Moreover, higher ionic conductivity can be obtained after B₂O₃ incorporation, where the optimal composition is 0.1 wt% B₂O₃ incorporated LATP and the ionic conductivity reaches 8.8×10^-5 S/cm, more than 3 times higher value than pristine LATP. More research could be followed for having higher ionic conductivity and density by optimizing the processing conditions. This facile approach for establishing higher ionic conductivity in LATP solid electrolytes could accelerate the commercialization of all-solid-state lithium batteries.

Multilayer Ceramic Capacitors (MLCCs) are essential passive components in the electronics industry, known for their high capacitance due to the multilayer structure comprising inner electrodes and dielectric layers. Nickel electrodes are commonly used in MLCCs as the inner electrodes, and to prevent oxidation during the co-firing of the dielectric layers with nickel electrodes, reducing atmosphere is required. However, reducing atmosphere sintering can also induce a reduction of the dielectric, necessitating precise control of oxygen partial pressure. To explore the possibility of using oxide electrodes that do not require reducing atmosphere sintering, we analyze the electrical properties of nickel oxide (NiO) as a potential candidate. As a preliminary study on its use as an alternative inner electrode, the correlation between microstructure and electrical properties of bulk NiO under different sintering conditions was investigated to gain insights into the conduction mechanisms of the material.

CNT fiber has been in the spotlight as a conductor, but the conductivity of CNT fibers do not match that of CNT. This study reveals that the conductivity of CNT fiber can be improved by depositing Al/Cu through vacuum evaporation. Cu is commonly used for deposition on CNT fibers. But low bonding strength of the interface between CNT and Cu could be a disadvantage. To overcome this, Al was deposited on the CNT fiber for forming aluminum carbide islands to increase the interfacial bonding strength. The conductivity characteristics were improved as the deposition time increased. The resistance was measured as a function of temperature, demonstrating that the temperature coefficient of resistance (TCR) is improved to be 241 ppm/℃ in comparison with that of as-received CNT fibers at -1,251 ppm/℃, when the CNT fibers are deposited with Al and Cu, respectively, for 90s and for 540s.

This study performs the thermal aging of chlorosulfonated polyethylene (CSPE) for 807.36 and 1,614.48 hours at 110℃, which is equivalent to 40 and 80 years of aging at 50℃ in nuclear power plants, respectively. Flat-type CSPEs were soaked in seawater for five days and then dried for five days at room temperature. Furthermore, the soaked CSPEs were cleaned for 5 days with fresh water and dried for 1,100 days at room temperature. Through this process, the log IV of the CSPEs decreases, whereas the dissipation factor of the CSPEs increases as thermally accelerated aged years increase at the measured frequency. Although the phase degree of the response voltage versus excitation voltage of the CSPEs increases, that of the response current versus excitation voltage decreases with the thermally accelerated aging. The thermal conductivity of the CSPEs increases slightly, but the thermal diffusivity does not vary with the thermally accelerated aged year increase. The displacement of the compressive strength of the CSPEs decreases gradually as the thermally accelerated aged years increase.

In this study, the volume resistivity of XLPE materials with various voltage ratings was discussed. The volume resistivity of the developed XPLE nanocomposite was measured, and the conductivity mechanism of the material was also examined. The ASTM D 257 and IEC 60093 measurement methods were used for these tests. The equipment was designed to measure up to a temperature of 200℃, and the electrode structure was designed to maintain the thickness and temperature uniformity of the sample. The conductivity of the sample decreased with temperature, and the samples reached saturation within 500s, after which the conductivity leveled off. By analyzing the current density and the electric field, we can well explain the electric conductivity behavior of our sample with the Schottky mechanism.

Hexagonal boron nitride particles (s-hBN) modified with 3-aminopropyl triethoxysilane (APTES) were used for the preparation of silicone composite materials. The microstructure of the composite materials was observed, and the thermal conduction and mechanical characteristics of the composite sheets were studied based on the compositions and microstructures. When a small amount of s-hBN particles was used, the thermal conductivity of the composite improved as a whole, and the tensile strength of the sheet also increased. The thermal conductivity and tensile strength of the composite in which a small amount of carbon fiber was added along with s-hBN were further improved. However, the use of carbon nanotubes with structural characteristics similar to those of carbon fiber resulted in lower thermal conductivity and tensile strength. Elastic silicone composites exhibiting 2.5 W/mK of thermal conductivity and a low hardness are expected to be used as thermally conductive interfacial sheet materials.

Electrical behaviors of plasma-sprayed Al₂O₃-TiO₂ coatings have been investigated in terms of their TiO₂ content. On increasing the TiO₂ content from 6 to 30 wt%, the DC electrical conductivity increased by several orders of magnitude. From impedance spectroscopy analysis, the total conductivity of the grains and grain boundaries and their respective activation energies were determined without the electrode effects that could impede ionic transfer. An electron transference number was also estimated, ranging between 6.5% and 7.3% for 13 wt% TiO₂ and between 0.4% and 0.7% for 30 wt% TiO₂ in the coating. Because of the high electronic contribution to the total conductivity, the Al₂O₃-TiO₂ coating could be a new candidate material to obtain superior electrical conductivity as well as corrosion and wear resistances.

In this paper, we fabricated flexible CNT/PVDF (carbon nanotube / polyvinylidene fluoride) piezoelectric composite device with flexible poly(3,4-ethylenedioxythiophene) : polystyrene sulfonate (PEDOT:PSS) conducting polymer electrode using spray coating method. We tried to improve the piezoelectric performance from the CNT/PVDF composite film by enhancing electrical conductivity of the PEDOT:PSS electrodes. Electrical conductivity of the PEDOT:PSS electrode was enhanced by dipping it into the EG (ethylene glycol) solvent. Changes of chemical composition of the PEDOT:PSS electrode were analyzed with the dipping time by XPS (x-ray photoelectron spectroscopy) in terms of oxygen (O1s). Finally, Piezoelectric performances such as output voltage and current were measured with the dipping time. We found that enhanced electrical conductivity of the PEDOT:PSS electrodes resulted in improvement of the piezoelectric performance of the CNT/PVDF films.

Thermal and electrical conductivities of the natural, artificial, and expandable graphites were analyzed after treatment in NaOH aqueous solution. In order to investigate the elimination of the oxidized groups and impurities on the graphite surfaces after NaOH treatment, the graphite samples were structurally characterized by using XRD, XPS, Raman, FE-SEM. The thermal and electrical conductivities of the graphite samples were significantly improved after NaOH treatment. These results were caused by the structural rehabiliation.

In this paper, the efficiency improvement of the heterojunction with intrinsic thin layer (HIT) solar cells is obtained by optimization process of p-type a-SiC:H as emitter. The optoelectronic of p-type a-SiC:H layers including the optical band-gap and conductivity under the methane gas content variation is conducted in detail. A significant increase in the Jsc by 1 mA/cm2 and Voc by 30 mV are attributed to enhanced photon-absorption due to broader band-gap of p-a-SiC:H and reduced band-offsets at p-side interface, respectively of HIT solar cells.

The conduction behavior and electron concentration change in a-IGZO thin-films according to the RTA (rapid thermal annealing) were studied. The electrical characteristics of TFTs (thin-film-transistors) annealed by different temperatures were measured. The sheet resistance, electron concentration, and oxygen vacancy of a-IGZO film were measured by the four-point-probe-measurement, hall-effect-measurement, and XPS analysis. The RTA process increased the driving current of IGZO TFTs but the VTH shifted to the negative direction at the same time. When the RTA temperature is higher than 250℃, the leakage current at off-state increased significantly. This is attributed to the increase of oxygen vacancy resulting in the increase of electron concentration. We demonstrate that the RTA is a promising process to adjust the VTH of TFT because the RTA process can easily modify the electron concentration and control the conductivity of IGZO film with short process time.

In this paper, we fabricated organic compounds detector using the MWCNT/PMMA (multi-walled carbon nanotube / polymethylmethacrylate) composite film. We used polymer film as a matrix material for the device framework, and introduced CNTs for reacting with the organic compounds resulting in changing electrical conductivity. Spray coating method was used to form the MWCNT/PMMA composite film detector, and pattern formation of the detector was done by shadow mask during the spray coating process. We investigated changes of electrical conductivity of the detector before and after the organic compounds exposure. Electrical conductivity of the detector tended to decrease after the exposure with various organic compounds such as acetone, tetrahydrofuran(THF), toluene, and dimethylformamide (DMF). Finally we conclude that organic compounds detection by the MWCNT/PMMA composite film detector was possible, and expect the feasibility of commercial MWCNT/PMMA composite film detector for various organic compounds.

The perovskite solid solutions of the Sr1-xMgxFe3+ 1-τFe4+ τO3-y system (x=0.0, 0.1, 0.2, and 0.3) were synthesized in N2 at 1,150℃. X-ray powder diffraction study assured that all the four samples had cubic symmetries(SM-0: 3.865 Å, SM-1: 3.849 Å, SM-2: 3.833 Å, and SM-3: 3.820 Å) and that the lattice volumes decreased steadily from 57.7 Å3 to 55.7 Å3 with x values. The nonstoichiometric chemical formulas were determined by Mohr salt analysis and with the increase of x values the amounts of Fe4+ ion and oxygen were decreased simultaneously. Thermal analysis showed that SM-0 started to lose its oxygen at 450℃ and SM-1, Sm-2, and SM-3 began to lose their oxygen at around 350～400℃. SM-0 showed almost reversible weight change in the cooling process. All the samples exhibited semiconducting behaviors in the temperature range of 10~400℃. Conductivities of the 4 samples were decreased in the order of SM-0, SM-1, SM-2, and SM-3 at constant temperature. The activation energies of the conductions were in the range of 0.176 eV～0.244 eV.

Citations

• Hydrogen production by isothermal thermochemical cycles using La0.8Ca0.2MeO3±δ (Me = Co, Ni, Fe and Cu) perovskites
  Alejandro Pérez, María Orfila, María Linares, Raúl Sanz, Javier Marugán, Raúl Molina, Juan A. Botas
  International Journal of Hydrogen Energy.2024; 52: 1101.     CrossRef

Sintering, microstructure, thermal conductivity and microwave dielectric properties of xLiF-(1-x)MgO ceramics (x=0.03-0.10 mol) were investigated. The high density was obtained in the specimens of x≥0.06, i.e., 0.04 LiF-0.96 MgO in mol, whereas the amount of 0.03 mol LiF was insufficient to densify. From the result that the contact flattening in the sintered specimen was observed, the densification occurred through the liquid-phase sintering. The specimen of x=0.06 showed the highest room-temperature thermal conductivity. Relative density, thermal conductivity, dielectric constant, and quality factor (Q x f) of the specimen for x=0.06 sintered at 900°C for 4 h were 97.8%, 39.2 Wm-1K-1, 9.45, and 14,671 GHz, respectively.

The purpose of this study is examining thermal dissipation materials for the lighting and radiate efficiency improvement of 8W LED and confirming the properness of the thermal dissipation materials for LED heat sink. Solid Works flow simulation on 8W class COB was done based on the material characteristics of thermal conductive polymer materials. According to the result of simulation, Al had better thermal dissipation performance than PET. Highest temperature was 7.6℃ higher while lowest temperature was 7.8℃ lower. The test on the heat sinks made by the materials, highest temperature was 4.1℃ higher and lowest temperature was 3.9℃ lower. It is possible to confirm that Al heat sink has better thermal dissipation efficiency because it has better dispersion of heat generated at junction temperature and less heat cohesion. The weight of PET heat sink was reduced than Al heat sink by 46.9% by the density difference between Al and PET. In conclusion, thermal dissipation performance of thermal conductive polymer is lower than Al material however, it is possible to lighting heat sink because thermal conductive polymer has better formability, has lower specific weight and enables various design options.

Because of the development of LED technology, products due to high output and compact, thematerial with high thermal conductivity has been developed. Now that heat radiating part of the LEDlamp is currently used for die casting of aluminum. The development of aluminum with excellent thermalconductivity is required. In this study, we measured the thermal properties and compared them while weproduced the alloy by changing the component of die casting aluminum. From this study, the thermalconductivity and thermal resistance of the developed alloy were superior to die casting aluminum.

In this study, we proposed CMP-PLAs to replace the Al heat sinks as heat sink materials, and investigated heat dissipation characteristics of the LED lighting devices using them. The crystallinity of the proposed CMP-PLA heat sinks decreased with increasing carbon nanotube contents in CMP-PLA. However, the thermal conductivity was improved with the increase of the carbon nanotube contents. The heat dissipation characteristics of the LED lighting devices using CMP-PLA heat sinks was improved with increasing carbon nanotube contents in CMP-PLA. For the LED lighting devices using CMP-PLA heat sinks with 40% carbon nanotube contents, the initial temperature measured at the heat sink plate was 27℃, which increased as time, and it was saturated around 56℃ after an hour. The LED lighting devices using CMP-PLA heat sinks are expected to be functional materials that can reduce their weight and improve their electric properties, compared to those using existing Al heat sinks.

In this paper, the characteristics of a carbon nanotube composite heat sink proposed to replace the advanced Al heat sinks for LED lighting devices were studied. Proposed CMP-PLA heat sink was made by mixing 20∼70 wt% carbon nanotube, 20∼70 wt% bio-degradable polymer of melt-blended PLA (poly lactic acid) and PBS (poly butylene succinate) and PLA nucleating agents composed of the mixture of soybean oil and biotites, at 150∼220℃ with 1,000∼1,500 rpm. Optical and electric characteristics of 7.5W LED lighting devices using heat sinks with such prepared CMP-PLA were investigated. And, the properties of the heat, which was not released from the CMP-PLA type heat sinks, was also investigated. The color temperature of LED lighting devices using the CMP-PLA heat sinks was 5,956 K,which is x= 0.32 and y= 0.34 in the XY chromaticity, and the color rendering index was 75. The luminous flux and the luminous efficiency of LED lighting devices using the CMP-PLA heat sinks was 540.6 lm and 72.68 lm/W respectively. Measured initial temperature of the heat sinks was 27℃, and their temperature increased as time to be saturated at 52℃ after an hour.

In this paper, heat-releasing composite sheets made of AlN, graphite, Al powder and acryl binder as thermoset were prepared using tape casting method, The crystal structure, morphology, thermal conductivity of heat-releasing composite sheet were measured by using X-ray diffractometer, field emission-scanning electron microscopy and laser flash instrument. It was found thermal conductivity of sheet was decided by solid content, composition including AlN, graphite, Al in heat-releasing composite sheets. As a result, 4.56W/mK of thermal conductivity could be obtained by using LFA 447.

In this paper, heat-releasing sheets made of AlN powder and acryl binder as thermoset were prepared using tape casting method. The crystal structure and morphology, the thermal properties as nonvolatile solid content and thermal conductivity, and the surface resistance of heat- releasing sheet were measured by using X-ray diffractometer, field emission-scanning electron microscopy, thermo gravimetric analyzer and laser flash instrument, and surface resistance meter. It was proved that thermal conductivity is greatly affected by the content of binder in heat-releasing sheet. Superior thermal conductivity above 3.5W/mK and suface resistance were obtained at heat-releasing sheet with above 90% of AlN powder.

Citations

• From Powder to Performance: A Review on the Synthesis and Densification of AlN for Advanced Thermal Management
  Panpan Du, Liang Wang, Yingying Shi, Zheng Wang
  Journal of the American Ceramic Society.2026;[Epub]     CrossRef

Citations

• Preparation and Characterization of Electrically and Thermally Conductive Polymeric Nanocomposites
  Mousam Choudhury, Smita Mohanty, Sanjay K Nayak, Rakesh Aphale
  Journal of Minerals and Materials Characterization and Engineering.2012; 11(07): 744.     CrossRef

Citations

• Photoluminescence Characteristics of ZnO Nano Needle-like Rods grown by the Hot Wall Epitaxy Method
  Sung-Hwan Eom, Yong-Dae Choi
  Transactions on Electrical and Electronic Materials.2007; 8(5): 191.     CrossRef