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1.
Adv Sci (Weinh) ; 10(25): e2300925, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37424035

RESUMO

Graphdiyne (GDY), a new 2D material, has recently proven excellent performance in photodetector applications due to its direct bandgap and high mobility. Different from the zero-gap of graphene, these preeminent properties made GDY emerge as a rising star for solving the bottleneck of graphene-based inefficient heterojunction. Herein, a highly effective graphdiyne/molybdenum (GDY/MoS2 ) type-II heterojunction in a charge separation is reported toward a high-performance photodetector. Characterized by robust electron repulsion of alkyne-rich skeleton, the GDY based junction facilitates the effective electron-hole pairs separation and transfer. This results in significant suppression of Auger recombination up to six times at the GDY/MoS2 interface compared with the pristine materials owing to an ultrafast hot hole transfer from MoS2 to GDY. GDY/MoS2 device demonstrates notable photovoltaic behavior with a short-circuit current of -1.3 × 10-5 A and a large open-circuit voltage of 0.23 V under visible irradiation. As a positive-charge-attracting magnet, under illumination, alkyne-rich framework induces positive photogating effect on the neighboring MoS2 , further enhancing photocurrent. Consequently, the device exhibits broadband detection (453-1064 nm) with a maximum responsivity of 78.5 A W-1 and a high speed of 50 µs. Results open up a new promising strategy using GDY toward effective junction for future optoelectronic applications.

3.
Materials (Basel) ; 14(16)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34442999

RESUMO

The 1D wire TaS3 exhibits metallic behavior at room temperature but changes into a semiconductor below the Peierls transition temperature (Tp), near 210 K. Using the 3ω method, we measured the thermal conductivity κ of TaS3 as a function of temperature. Electrons dominate the heat conduction of a metal. The Wiedemann-Franz law states that the thermal conductivity κ of a metal is proportional to the electrical conductivity σ with a proportional coefficient of L0, known as the Lorenz number-that is, κ=σLoT. Our characterization of the thermal conductivity of metallic TaS3 reveals that, at a given temperature T, the thermal conductivity κ is much higher than the value estimated in the Wiedemann-Franz (W-F) law. The thermal conductivity of metallic TaS3 was approximately 12 times larger than predicted by W-F law, implying L=12L0. This result implies the possibility of an existing heat conduction path that the Sommerfeld theory cannot account for.

4.
Korean J Fam Med ; 41(6): 398-403, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32418394

RESUMO

BACKGROUND: Systemic Clinic Outcome and Routine Evaluation (SCORE-15) is a compact scale that contains the most critical family function assessment tools including assessments of the strengths, adaptability, and communication among family members. It has been translated into other languages in the United States and Europe. This study aimed to verify the reliability and validity of SCORE-15 with a small research population and justify its applicability in Korea. METHODS: SCORE-15 is a self-reporting family function measurement tool for each family member over the age of 11 years. This study used the Family Communication Scale (FCS) included in the Family Adaptability and Cohesion Evaluation Scales (FACES) IV package and FACES in FACES-III to verify the validity of the Korean-translated SCORE-15. Cronbach's α value was calculated to check the reliability of SCORE-15. Data were analyzed using STATA ver. 15.0 (Stata Corp., College Station, TX, USA). RESULTS: The study analyzed the correlation between FACES-III and SCORE-15 and FCS and SCORE-15 so that there was a significant static correlation in both comparisons (r=0.72 and r=0.81, respectively). Also, the research compared each subscale to analyze the correlation and the range was 0.47 to 0.95. The total SCORE-15 Cronbach's α value was 0.92 and those values of the subscales for family strengths, family communication, and family difficulty were 0.89, 0.73, and 0.87, respectively (P<0.001). CONCLUSION: Our study was the first to validate the Korean SCORE-15, which can be used as an appropriate shortform indicator for evaluating family function and changes in detecting therapeutic improvements in Korea.

5.
ACS Appl Mater Interfaces ; 10(20): 17375-17382, 2018 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-29722520

RESUMO

The spontaneous separation of a polymer thin film from a substrate is an innovative technology that will enable material recycling and reduce manufacturing cost in the film industry, and this can be applied in a wide range of applications, from optical films to wearable devices. Here, we present an unprecedented spontaneous strategy for separating transparent polymer films from substrates on the basis of microbubble generation using nanocapsules containing an evaporable material. The core-shell nanocapsules are prepared from poly(methyl methacrylate)-polyethyleneimine nanoparticles via the encapsulation of methylcyclohexane (MCH). A spherical nanostructure with a vaporizable core is obtained, with the heat-triggered gas release ability leading to the formation of microbubbles. Our separation method applied to transparent polymer films doped with a small amount of the nanocapsules encapsulating evaporable MCH enables spontaneous detachment of thin films from substrates via vacuum-assisted rapid vaporization of MCH over a short separation time, and clear detachment of the film is achieved with no deterioration of the inherent optical transparency and adhesive property compared to a pristine film.

6.
ACS Appl Mater Interfaces ; 9(49): 43105-43112, 2017 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-29160058

RESUMO

With increasing demand for transparent conducting electrodes, graphene has attracted considerable attention, owing to its high electrical conductivity, high transmittance, low reflectance, flexibility, and tunable work function. Two faces of single-layer graphene are indistinguishable in its nature, and this idea has not been doubted even in multilayered graphene (MLG) because it is difficult to separately characterize the front (first-born) and the rear face (last-born) of MLG by using conventional analysis tools, such as Raman and ultraviolet spectroscopy, scanning probe microscopy, and sheet resistance. In this paper, we report the striking difference of the emission pattern and performance of transparent organic light-emitting diodes (OLEDs) depending on the adopted face of MLG and show the resolved chemical and physical states of both faces by using depth-selected absorption spectroscopy. Our results strongly support that the interface property between two different materials rules over the bulk property in the driving performance of OLEDs.

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