• Journal of Electrochemical Science and Technology
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• v.11 no.3
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• pp.282-290
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• 2020

In this article, we report the effect of blended cathode materials on the performance of all-solid-state lithium-ion batteries (ASLBs) with oxide-based organic/inorganic hybrid electrolytes. LiFePO₄ material is good candidates as cathode material in PEO-based solid electrolytes because of their low operating potential of 3.4 V; however, LiFePO₄ suffers from low electric conductivity and low Li ion diffusion rate across the LiFePO₄/FePO₄ interface. Particularly, monoclinic Li₃V₂(PO₄)₃ (LVP) is a well-known high-power-density cathode material due to its rapid ionic diffusion properties. Therefore, the structure, cycling stability, and rate performance of the blended LiFePO₄/Li₃V₂(PO₄)₃ cathode material in ASLBs with oxidebased inorganic/organic-hybrid electrolytes are investigated by using powder X-ray diffraction analysis, field-emission scanning electron microscopy, Brunauer-Emmett-Teller sorption experiments, electrochemical impedance spectroscopy, and galvanostatic measurements.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.118-118
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• 2011

The Nano-Floating Gate Memory(NFGM) devices with ZnO:Cu thin film embedded in Al2O3 and AlOx-SAOL were fabricated and the electrical characteristics were evaluated. To further improve the scaling and to increase the program/erase speed, the high-k dielectric with a large barrier height such as Al2O3 can also act alternatively as a blocking layer for high-speed flash memory device application. The Al2O3 layer and AlOx-SAOL were deposited by MLD system and ZnO:Cu films were deposited by ALD system. The tunneling layer which is consisted of AlOx-SAOL were sequentially deposited at $100^{\circ}C$. The floating gate is consisted of ZnO films, which are doped with copper. The floating gate of ZnO:Cu films was used for charge trap. The same as tunneling layer, floating gate were sequentially deposited at $100^{\circ}C$. By using ALD process, we could control the proportion of Cu doping in charge trap layer and observe the memory characteristic of Cu doping ratio. Also, we could control and observe the memory property which is followed by tunneling layer thickness. The thickness of ZnO:Cu films was measured by Transmission Electron Microscopy. XPS analysis was performed to determine the composition of the ZnO:Cu film deposited by ALD process. A significant threshold voltage shift of fabricated floating gate memory devices was obtained due to the charging effects of ZnO:Cu films and the memory windows was about 13V. The feasibility of ZnO:Cu films deposited between Al2O3 and AlOx-SAOL for NFGM device application was also showed. We applied our ZnO:Cu memory to thin film transistor and evaluate the electrical property. The structure of our memory thin film transistor is consisted of all organic-inorganic hybrid structure. Then, we expect that our film could be applied to high-performance flexible device.----못찾겠음......

• Journal of the Microelectronics and Packaging Society
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• v.24 no.4
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• pp.79-84
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• 2017

The solar cells should be protected from the moisture and oxygen in order to sustain the properties and reliability of the devices. In this research, we prepared the protection films on the flexible plastic substrates by spray coating method using organic-inorganic hybrid solutions. The protection characteristics were studied depending on the various process conditions (nozzle distance, thicknesses of the coatings, film structures). The organic-inorganic solutions for the protection film layer were synthesized by addition of $Al_2O_3$ ($P.S+Al_2O_3$) and $SiO_2$ ($P.S+SiO_2$) nano-powders into PVA (polyvinyl alcohol) and SA (sodium alginate) (P.S) organic solution. The optical transmittances of the protection film with the thicknesses of $5{\mu}m$ showed 91%. The optical transmittance decreased from 81.6% to 73.6% with the film thickness increased from $78{\mu}m$ to $178{\mu}m$. In addition, the protective films were prepared on the PEN (polyethylene naphthalate), PC (polycarbonate) single plastic substrates as well as the Acrylate film coated on PC substrate (Acrylate film/PC double layer), and $Al_2O_3$ film coated on PEN substrate ($Al_2O_3$ film/PEN double layer) using the $P.S+Al_2O_3$ organic-inorganic hybrid solutions. The optimum protection film structure was studied by means of the measurements of water vapor transmittance rate (WVTR) and surface morphology. The protective film on PEN/$Al_2O_3$ double layer substrate showed the best water protective property, indicating the WVTR value of $0.004gm/m^2-day$.

• Korean Journal of Materials Research
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• v.31 no.9
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• pp.496-501
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• 2021

Metal halide perovskite nanocrystals, due to their high absorption coefficient, high diffusion length, and photoluminescence quantum yield, have received significant attention in the fields of optoelectronic applications such as highly efficient photovoltaic cells and narrow-line-width light emitting diodes. Their energy band structure can be controlled via chemical exchange of the halide anion or monovalent cations in the perovskite nanocrystals. Recently, it has been demonstrated that chemical exfoliation of the halide perovskite crystal structure can be achieved by addition of organic ligands such as n-octylamine during the synthetic process. In this study, we systematically investigated the quantum confinement effect of methylammonium lead bromide (CH₃NH₃PbBr₃, MAPbBr₃) nanocrystals by precise control of the crystal thickness via chemical exfoliation using n-octylammonium bromide (OABr). We found that the crystalline thickness consistently decreases with increasing amounts of OABr, which has a larger ionic radius than that of CH₃NH₃⁺ ions. In particular, a significant quantum confinement effect is observed when the amounts of OABr are higher than 60 %, which exhibited a blue-shifted PL emission (~ 100 nm) as well as an increase of energy bandgap (~ 1.53 eV).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.477-480
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• 2002

Si-O-C(-H) thin film with a tow dielectric constant were deposited on a P-type Si(100) substrate by an inductively coupled plasma chemical vapor deposition (ICPCVD). Bis-trimethylsilymethane (BTMSM, H$_{9}$C$_3$-Si-CH$_2$-Si-C$_3$H$_{9}$) and oxygen gas were used as Precursor. Hybrid type Si-O-C(-H) thin films with organic material have been generated many voids after annealing. Consequently, the Si-O-C(-H) films can be made a low dielectric material by the effect of void. The surface characterization of Si-O-C(-H) thin films were performed by SEM(scanning electron microscope). The characteristic analysis of Si-O-C(-H) thin films were performed by X-ray photoelectron spectroscopy (XPS).

• ETRI Journal
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• v.36 no.5
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• pp.847-855
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• 2014

We developed a highly refractive index planarization layer showing a very smooth surface for organic light-emitting diode (OLED) light extraction, and we successfully prepared a highly efficient white OLED device with an embossed nano-structure and highly refractive index planarization layers. White OLEDs act as an internal out-coupling layer. We used a spin-coating method and two types of $TiO_2$ solutions for a planarization of the embossed nano-structure on a glass substrate. The first $TiO_2$ solution was $TiO_2$ sol, which consists of $TiO_2$ colloidal particles in an acidic aqueous solution and several organic additives. The second solution was an organic and inorganic hybrid solution of $TiO_2$. The surface roughness ($R_a$) and refractive index of the $TiO_2$ planarization films on a flat glass were 0.4 nm and 2.0 at 550 nm, respectively. The J-V characteristics of the OLED including the embossed nano-structure and the $TiO_2$ planarization film were almost the same as those of an OLED with a flat glass, and the luminous efficacy of the aforementioned OLED was enhanced by 34% compared to that of an OLED with a flat glass.

• Journal of the Semiconductor & Display Technology
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• v.16 no.2
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• pp.19-26
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• 2017

The cure properties of ethoxysilyl bisphenol A type epoxy resin (Ethoxysilyl-DGEBA) systems with different hardeners were investigated, comparing with DGEBA and Diallyl-DGEBA epoxy resin systems. The cure kinetics of these systems were analyzed by differential scanning calorimetry with an isothermal approach, and the kinetic parameters of all systems were reported in generalized kinetic equations with diffusion effects. The Ethoxysilyl-DGEBA epoxy resin system showed lower cure conversion rates than DGEBA and Diallyl-DGEBA epoxy resin systems. The conversion rates of these epoxy resin systems with DDM hardener are lower than those with HF-1M hardener. It can be considered that the optimum hardener for Ethoxysilyl-DGEBA epoxy resin system is Phenol Novolac type. These lower cure conversion rates in the Ethoxysilyl-DGEBA epoxy resin systems could be explained by the retardation of reaction molecule movements according to the formation of organic-inorganic hybrid network structure by epoxy and ethoxysilyl group in Ethoxysilyl- DGEBA epoxy resin system.

• Elastomers and Composites
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• v.57 no.2
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• pp.62-72
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• 2022

Passive daytime radiative cooling (PDRC) is attracting increasing attention as an eco-friendly technology that can save cooling energy by not requiring an external power supply. An ideal PDRC structure should improve solar reflectance and emissivity within the atmospheric spectral window. Early designs of photonic crystal materials demonstrated the benefits of PDRC. Since then, functional arrangements of polymer-based radiative cooling materials have played an important role and are rapidly expanding. This review summarizes the known inorganic, organic, and hybrid materials for PDRC. The review also provides a complete understanding of PDRC and highlights its practical applications.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.115.1-115.1
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• 2016

Electrochemical anodization has been interested due to its useful way for the nano-scale architecture of metal oxides obtained from a metal substrate. By using this method, it is easy to control the morphology of the oxide materials by controlling electrochemical conditions. Among oxide materials obtained from the transition metals such as Ti, V, W, etc., in this paper, the morphological study of anodized $TiO_2$ was employed at various voltage conditions in fluoric based electrolyte, and the effects of applied voltage (sweep rate and retention time) on the tube morphologies were investigated. Furthermore, by using anodization of tungsten substrate (W), we fabricated the porous structure of $WO_3$ and provided merits of tailored structure for the hybridization of inorganic and organic materials as electrochromic (EC) applications. The hybrid porous $WO_3$ shows multi-chromic properties during the EC reactions at specific voltage conditions. From these results, the anodization process with tailoring nano-structure is one of the promising methods for EC applications.

• Polymer(Korea)
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• v.37 no.1
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• pp.34-40
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• 2013

Commercially available polyamide thermoplastic elastomer (PA-TPE) was blended with hybrid filler which was prepared by means of the reaction between polyhedral oligomeric silsesquioxane (POSS) containing amine group and toluene diisocyanate (TDI)-caprolactam (CL) to explore the effect of blending the hybrid filler with the TPE. The chemical structure of the filler was identified by using FTIR and $^1H$ NMR. The composites, PA-TPE/POSS-(TDI+CL), which were the blends of TDI+CL modified POSS filler and PA-TPE up to 7 wt%, showed better elastic recovery delivered from lower tension setting compared to the PA-TPE and the PA-TPE/octaphenyl POSS blend. In addition the tensile strength and the initial modulus increased with increasing the hybrid filled content. Consequently it was assumed that the POSS-(TDI+CL) filler was a suitable material for enhancing strength and modulus without loss of elastic properties for the original PA-TPE.