Sung-Joo Oh

While colloidal semiconductor nanocrystal (NC) is preferred for use in solution-based optoelectronic devices, the large number of surface defects associated with its high surface-to-volume ratio degrades the optimal performance of NC-based devices due to the extensive trapping of free carriers available for charge transport. Here, we studied a simple and effective strategy to control the degree of passivation and doping level of solution-deposited ZnO NC films by infilling with ultra-thin Al2O3

Efficient methods for the controlled syntheses of metal nanocrystals are important for emergingelectronics and catalysis applications. In this report, we present a solution-based method for thefabrication of Pt-coated Ag nanocrystal (NC) thinfilms through the use of ligand-exchange andelectroless deposition. We successfully prepared uniform or bumpy Ag@Pt core/shell structures, as wellas Ag–Pt alloy structures, through control of the reducing agents. Wefirst report the Ag–Pt alloystructures can

Wearable sensors designed for strain, pressure, and temperature measurements are essential for monitoring human movements, healthstatus, physiological data, and responses to external stimuli. Notably, recent research has led to the development of high-performancewearable sensors using innovative materials and device structures that exhibit ultra-high sensitivity compared with their commercialcounterparts. However, the quest for accurate sensing has identified a critical challenge. Specifically,

The physical properties of metal-based structural materials, such as hardness, strength andtoughness, are directly or indirectly affected by residual stress inside or on the surface of the given part. Repeatedrapid heating and cooling during the additive manufacturing process causes thermal gradients and expansionand contraction in the material, which causes residual stress. Tensile residual stresses are known to exist onthe surface of additive manufactured products and should be kept to a minim

Currently, photodetectors are being extensively studied and developed for next-generation applications, such as in autonomous vehicles and image sensors. In this regard, all-inorganic metal halide perovskite (CsPbX3; X = Cl, Br, and I) nanocrystals (NCs) have emerged as promising building blocks for various applications owing to their high absorption coefficients, tunable bandgaps, high defect tolerances, and solution processability. These features, which are typically required for the developme

In this study, we introduce a strategy to introduce solution-processed interfacial layers in nanocrystal(NC) thinfilms to fabricate high-performance strain sensors. SiO2 interfacial layers are chemicallyintroduced in ligand-exchanged Ag NC thinfilms to increase the tunneling gap or inter-particle distancebetween each Ag NC. In this way, the charge-transport mechanism is manipulated, leading to uniqueelectromechanical properties with a high gauge factor. All solution-processed strain gauge sensor

Wearable multi-sensors based on nanocrystals have attracted significant attention, and studies on patterning technology to implement such multi-sensors are underway. Conventional patterning processes may affect material properties based on high temperatures and harsh chemical conditions. In this study, we developed an inkjet printing technique that can overcome these drawbacks through the application of patterning processes at room temperature and atmospheric pressure. Nanocrystal-based ink is u

AlSi10Mg alloys are being actively studied through additive manufacturing for application in the automobile and aerospace industries because of their excellent mechanical properties. To obtain a consistently high quality product through additive manufacturing, studying the flowability and spreadability of the metal powder is necessary. AlSi10Mg powder easily forms an oxide film on the powder surface and has hydrophilic properties, making it vulnerable to moisture. Therefore, in this study, AlSi1

In recent times, wearable sensors have attracted significant attention in various research fields and industries. The rapid growth of the wearable sensor related research and industry has led to the development of new devices and advanced applications such as bio-integrated devices, wearable health care systems, soft robotics, and electronic skins, among others. Nanocrystals (NCs) are promising building blocks for the design of novel wearable sensors, due to their solution processability and tun

In this study, we developed a fabrication method of conductive and transparent Ag mesh electrodes on flexible polymer film at temperatures lower than 100 °C. Random patterned Ag mesh film was fabricated on a flexible PET substrate over 15×15 cm2 by a self-assembly process. It became conductive by a coupling process at low temperatures. The coupled Ag mesh film showed more than 88% transmittance in visible wavelength and less than 8.2 Ω sq−1 in sheet resistance with figure of merit (FoM) value of

Co-Cr alloys are widely used in cutting tools and turbine components due to their high strength and resistance against wear and corrosion. However, scrap generated during hardfacing is often discarded due to impurities and oxidation, and research on its recycling remains limited. This study aimed to optimize the recycling process of Stellite 6 scrap to reduce waste and minimize costs while maintaining material quality. Melting, casting, and powdering processes were designed using HSC Chemistry,