김재원 교수

Improved performance in plasmonic organic solar cells (OSCs) and organic light-emitting diodes (OLEDs) via strong plasmon-coupling effects generated by aligned silver nanowire (AgNW) transparent electrodes decorated with core-shell silver-silica nanoparticles (Ag@SiO₂ NPs) is demonstrated. NP-enhanced plasmonic AgNW (Ag@SiO₂ NP-AgNW) electrodes enable substantially enhanced radiative emission and light absorption efficiency due to strong hybridized plasmon coupling between

Abstract This work deals with the investigation of burn‐in loss in ternary blended organic photovoltaics (OPVs) prepared from a UV‐crosslinkable semiconducting polymer (P2FBTT‐Br) and a nonfullerene acceptor (IEICO‐4F) via a green solvent process. The synthesized P2FBTT‐Br can be crosslinked by UV irradiation for 150 s and dissolved in 2‐methylanisole due to its asymmetric structure. In OPV performance and burn‐in loss tests performed at 75 °C or AM 1.5G Sun illumination for 90 h, UV‐crosslinked

Zn 1 − x Mg x O thin films on (001) sapphire substrates were deposited using pulsed laser deposition. As the substrate temperature increased, the Mg content in the Zn1−xMgxO thin films increased and the photoluminescence (PL) peak position of the Zn1−xMgxO thin films shifted from 370to356nm, indicating a band gap expansion. Variations of the structural, electrical, and optical properties of Zn1−xMgO thin films have been observed and analyzed by x-ray diffraction, Hall measurements, and PL measur

This paper presents an innovative approach that uses a pulse-profile to improve the welding quality of CP1180 steel in resistance spot welding process. Three pulses with two cooling times were used in the developed multi-pulse welding (MPW) schedule. The experimental results show that the first pulse increases the contact area between the sheets to improve the current flow pattern. The second pulse was designed to extend the sheet-to-sheet contact area and corona bond for preventing rapid nugget

Sporting championships and other media events can induce very strong feelings of co-presence that can change communication patterns within large communities. Live tweeting reactions to media events provide high-resolution data with time-stamps to understand these behavioral dynamics. We employ a computational focus group method to identify a population of 790,744 international Twitter users, and we track their behavior before, during, and after the 2014 FIFA World Cup. We pick, in particular, a

Random configuration approach simultaneously enhances charge mobility, solubility in a green solvent, and flexibility of a semiconducting polymer.

A well-established xenoandrogen, tributyltin (TBT) causes sexual interferences in various animal models including gastropods. In bivalves, the disrupting effects of TBT on reproduction are largely unevaluated. In this study, we carried out a test on reproduction of the bivalve (Gomphina veneriformis) affected by TBT (0.4, 0.6, and 0.8 μg L−1). The experimental period was 36 weeks, starting in October during the inactive stage of the clam's reproductive cycle. The sex ratio (F:M) was 1:1.00 in th

Semiconducting polymers consisting of (E)-1,2-di(thiophen-2-yl)ethene (TVT) derivatives and benzo[1,2-b:4,5-b′]dithiophene with conjugated thiophene side chains (BDTT) were designed and synthesized to investigate the effect of fluorine and cyano groups in the 3-position of the thiophene ring in TVT on the photovoltaic properties. The corresponding PBDTT-TVT, PBDTT-FTVT, and PBDTT-CNTVT copolymers containing TVT, difluoro TVT (FTVT), and dicyano TVT (CNTVT), respectively, demonstrated considerabl

Phenyl-C₆₁-butyric acid methyl ester (PCBM) can be used as a passivation material in perovskite solar cells (PeSCs) in order to reduce the trap site of the perovskite. Here, we show that a thick PCBM layer can form a smoother surface on the SnO₂ substrate, improving the grain size and reducing the microstrain of the perovskite. High-temperature annealing treatment of PCBM layer not only increases its solvent resistance to perovskite precursor or antisolvent, but also enhanc

Abstract Power conversion efficiencies (PCEs) of glove‐box (GB) processed, two‐component, single‐junction organic solar cells (OSCs) have recently exceeded 18%. However, their mass‐scale manufacture using roll‐to‐roll (R2R) coating techniques is impracticable if they must be fabricated in an air‐free environment. From a commercialization perspective, efficient air‐processed OSCs are of much greater interest than GB‐processed devices since the vast majority of R2R‐manufacturing infrastructure is

Perovskite solar cells (PSCs) are now approaching their theoretical limits and the optimization of the auxiliary layers is crucial for fully exploiting the potential of perovskite materials. In this study, NiO x as a hole‐transport layer (HTL) for inverted p–i–n PSCs is focused on. Sputtered NiO x is an attractive p‐type HTL owing to its facile processing, wide energy bandgap that prevents electron transfer, high transparency, stability, and effective hole extraction. Despite substantial researc

Abstract The development of solution‐processed field effect transistors (FETs) based on organic and hybrid materials over the past two decades has demonstrated the incredible potential in these technologies. However, solution processed FETs generally require impracticably high voltages to switch on and off, which precludes their application in low‐power devices and prevent their integration with standard logic circuitry. Here, a universal and environmentally benign solution‐processing method for

Abstract Organic solar cells (OSCs) have reached an outstanding certified power conversion efficiency (PCE) of over 19% in single junction and 20% in tandem architecture design. Such high PCEs have emerged with outstanding Y-shaped Y6 non-fullerene acceptors (NFAs), together with PM6 electron donor polymers. PCEs are on the rise for small-area OSCs. However, large-area OSC sub-modules are still unable to achieve such high PCEs, and the highest certified PCE reported so far is ∼12% having an area