Showing papers by "Jin Young Oh published in 2015"
TL;DR: A stretchable polymer channel layer for organic field-effect transistors is obtained by spin-coating a blend solution of polythiophene and rubber polymer with large stretchability of the polythyphene film layer.
Abstract: A stretchable polymer channel layer for organic field-effect transistors is obtained by spin-coating a blend solution of polythiophene and rubber polymer. A network of the polythiophene nanofibril bundles surface-embedded in the rubber matrix allows large stretchability of the polythiophene film layer.
151 citations
TL;DR: Results suggest that ZrO2:B thin films could be used for low-temperature, solution-processed surface-modified flexible devices.
Abstract: A solution-processed boron-doped peroxo-zirconium oxide (ZrO2:B) thin film has been found to have multifunctional characteristics, providing both hydrophobic surface modification and a chemical glue layer. Specifically, a ZrO2:B thin film deposited on a hydrophobic layer becomes superhydrophilic following ultraviolet–ozone (UVO) treatment, whereas the same treatment has no effect on the hydrophobicity of the hydrophobic layer alone. Investigation of the ZrO2:B/hydrophobic interface layer using angle-resolved X-ray photoelectron spectroscopy (AR XPS) confirmed it to be chemically bonded like glue. Using the multifunctional nature of the ZrO2:B thin film, flexible amorphous indium oxide (In2O3) thin-film transistors (TFTs) were subsequently fabricated on a polyimide substrate along with a ZrO2:B/poly-4-vinylphenol (PVP) dielectric. An aqueous In2O3 solution was successfully coated onto the ZrO2:B/PVP dielectric, and the surface and chemical properties of the PVP and ZrO2:B thin films were analyzed by contac...
35 citations
TL;DR: In this paper, a simple approach to improve the wettability of poly(3,4-ethylene-dioxy-thiophene):poly-(styrenesulfonate) (PEDOT:PSS) polymer on a graphene surface by mixing it with a nonionic small molecule surfactant (Triton X-100).
28 citations
TL;DR: It is suggested that mixing high-RR and low-RR polymers may be a good strategy to optimize the electrical properties of polythiophenes for target applications.
Abstract: Morphological control over polythiophenes has been widely studied; however the impacts of regioregularity (RR) and molecular weight (MW) on their structural development have not been investigated systematically. This study examined a representative polythiophene, poly(3-hexylthiophene) (P3HT), to reveal that small differences in the RR can produce a large difference in the growth of nanofibrils. Low-RR P3HTs generated neat long nanofibrils (LNFs), whereas high-RR P3HTs formed short nanofibrils (SNFs). This study identified a critical RR (96–98%) depending on their MW, below which P3HT grew into LNFs and above which P3HT grew into SNFs. This study also found that the mixing ratio between high-RR P3HT and a low-RR P3HT in the solution phase is strongly correlated with the relative populations of SNF and LNF in the coated film. This study suggested that mixing high-RR and low-RR polymers may be a good strategy to optimize the electrical properties of polythiophenes for target applications. As an example, a m...
19 citations
TL;DR: AD and clinical depression interact closely, and causal relationships between the two conditions have frequently been observed, and Physicians should consider mental health interventions cautiously.
Abstract: Atopic dermatitis (AD) is characterized by pruritic and eczematous skin lesions, which often cause depressive symptoms, anxiety, stress, sleep disturbances, social withdrawal, and stigmatization.In total, 23,442 subjects (434 AD patients and 23,008 control subjects) aged 19 years or older and without a history of major medical illness or depressive disorders were selected from The Fifth Korea National Health and Nutrition Examination Survey 2007-2012. Following the initial selection, 2,170 age- and sex-matched control subjects were selected using 1:5 propensity score matching. Multiple logistic regression analysis was performed to identify the presence of depressive symptoms of at least 2 weeks in duration.The demographic, socioeconomic, and clinical characteristics of AD patients and control subjects were presented and compared, and some variables differed significantly between groups. Presence of depressive symptoms was set as dependent variable, and multiple logistic regression analysis was performed as follows: (1) unadjusted; (2) with alcohol use, exercise status, smoking status, and body mass index (BMI) adjusted for; and (3) with alcohol use, exercise status, smoking status, marital status, occupation, BMI, total caloric intake, history of hypertension, and history of diabetes mellitus adjusted for. Depressive symptoms were significantly higher (odds ratios, 1.46, 1.40, and 1.36; 95% confidence intervals, 1.09-1.95, 1.0.4-1.88, and 1.01-1.85, respectively) in AD patients relative to those of matched controls.AD and clinical depression interact closely, and causal relationships between the two conditions have frequently been observed. Physicians should consider mental health interventions cautiously. It is particularly important that primary care physicians provide comprehensive, continuous long-term care.
19 citations
TL;DR: To demonstrate the capability of the siloxane chain-based hydrophobizer to serve as a highly robust chemical surface modifier, two applications are presented: the formation of fine metal nanoparticles with a narrow size distribution by thermal aggregation of a metal thin film and the selective deposition of a ruthenium thin film by atomic layer deposition.
11 citations
TL;DR: The role of Li ions in lowering the dehydroxylation temperature of non-aqueous sol-gel inks for metal oxide thin film transistors (TFTs) was demonstrated for the first time in this article.
Abstract: The role of Li ions in lowering the dehydroxylation temperature of non-aqueous sol–gel inks for metal oxide thin film transistors (TFTs) was demonstrated for the first time. As a key mechanism in the lowering of the dehydroxylation temperature, the hydration of sol–gel inks by Li ions, which have a high charge density, was verified through various material analysis tools, such as Raman spectroscopy, TG-DTA, spectroscopic ellipsometry, XPS, and FT-IR. The hydration effect of Li ions on electronic properties was confirmed. This was done by evaluating the electrical properties of metal oxide TFTs that were fabricated at 300 °C using various kinds of sol–gel inks with and without Li ions. The results revealed that the dehydroxylation temperature was typically lowered by about 20 to 50 °C with the addition of Li ions to various kinds of non-aqueous sol–gel inks. Moreover, the Li-added metal oxide TFTs had mobilities that were several times higher than those of their undoped counterparts.
7 citations
Journal Article•
TL;DR: Serum 25(OH)D and PTH concentrations are not independently associated with serum lipid levels or an increased risk of dyslipidemia in the Korean population ≥ 50 years.
Abstract: Background: In this study, we investigated the relation of serum 25-hydroxyvitamin D (25(OH)D) and parathyroid hormone (PTH) concentrations with the risk of dyslipidemia in Korean adults aged 50 years and older, by using the most recent available Korean National Health and Nutrition Examination Surveys data. Methods: The sample of this population-based cross-sectional study consisted of 467 Korean adults who participated in the fifth Korean National Health and Nutrition Examination Surveys conducted in 2011. Participants who were taking lipid medications were excluded. Serum 25(OH)D concentrations were measured with radioimmunoassay, and serum PTH concentrations were measured with chemiluminescence assay. Results: The median concentrations of serum 25(OH)D and PTH for the entire group were 17.25 ng/mL and 65.07 pg/mL, respectively. In logistic regression analyses, the serum 25(OH)D and PTH concentrations were not significantly associated with the risk of dyslipidemia after adjustment for age, region, income, education level, smoking status, alcohol intake, and physical activity (p > 0.05). Conclusion: Serum 25(OH)D and PTH concentrations are not independently associated with serum lipid levels or an increased risk of dyslipidemia in the Korean population ≥ 50 years.
2 citations
TL;DR: In this article, the authors examined solution-processed alkaline-earth-metal doped gallium indium oxide (GIO) thin film transistors and studied the relationship between the dopant species and the threshold voltage (Vth) stability.
Abstract: We examined solution-processed alkaline-earth-metal doped gallium indium oxide (GIO) thin film transistors (TFT) and studied the relationship between the dopant species and the threshold voltage (Vth) stability. As the atomic number of the dopant increases, the amount of oxygen vacancies, which act as the major defect sites, decreased and the Vth stability is enhanced. The electron trapping times and total defect sites were quantitatively calculated. Particularly, Sr-doped GIO TFT show the highest Vth stability under positive gate bias and the origin of Vth stability enhancement is deduced by using the partial charge model and reaction kinetics.
1 citations