Grazing-Incidence X-ray Diffraction을 이용한 유기반도체 구조 분석과 양극성 유기트랜지스터 어레이 응용

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Molecular n-type doping for air-stable electron transport in vacuum-processed n-channel organic transistors

The effects of n-type doping on the air-stability of vacuum-processed n-channel organic transistors have been investigated using perylene diimides and pyronin B as the active layer and dopant, respectively. Systematic studies on the influence of doping location revealed the n-type doping of bulk active layer or channel region significantly improves air-stability by compensating for the trapped electrons with the donated mobile electrons. Although n-type doping at the electrode contact could readily turn on the devices, it could not confer air-stable electron transport. The described approach would open up opportunities to enable and improve the stability of n-channel organic transistors in air.open23

A facile synthesis of polypyrrole nanotubes using a template-mediated vapor deposition polymerization and the conversion to carbon nanotubes

Polypyrrole (PPy) nanotubes with highly uniform surface and tunable wall thickness were fabricated by one-step vapor deposition polymerization (VDP) using anodic aluminium oxide (AAO) template membranes, and transformed into carbon nanotubes through a carbonization process

유기 트랜지스터 기반 유연/신축성 센서

Molecule-based organic electronics has been regarded as a core component of future electronics such as wearable, attachable, and implantable electronics. Recent advances in the internet of things (IoT) platform have also given a possibility to organic electronics for applications as high-performance sensors owing to advantages of organic semiconductors, including abilities of molecule design, flexibility/stretchability, cost-efficiency, and mass-production. Herein, we introduce the recent progress of organic transistor-based sensors depending on types of external stimuli (i.e., chem/biosensor, photosensor, and pressure sensors). In addition, the potential of organic electronics for next-generation electronic devices will be described.2

Facile fabrication of polymer and carbon nanocapsules using polypyrrole core/shell nanomaterials

Core/shell nanomaterials composed of only polypyrroles (PPys) were fabricated by microemulsion polymerization using two oxidants with different chemical oxidation potentials, and used as a precursor for the fabrication of PPy and carbon nanocapsules.This work has been financially supported by the BK 21 program of the Korean Ministry of Education and by KOSEF through the HOMRC

A novel synthesis of nanocapsules using identical polymer core/shell nanospheres

Polymer nanocapsules were synthesized using core/shell nanospheres composed of an identical polymer. Linear polypyrrole (PPy)/crosslinked PPy core/shell nanospheres were synthesized stepwise by microemulsion polymerization using two oxidants with different chemical oxidation potentials, i.e. copper(II) chloride and iron(III) chloride. Coupled with the characteristics of the O/W microemulsion polymerization, the hydrophilic oxidants with different chemical oxidation potentials produced PPys with different solubility in alcohol. The linear PPy core and cationic surfactants could be removed by one-step solvent etching process simultaneously, and crosslinked PPy nanocapsules were obtained. The pore size and shell thickness of PPy nanocapsules were tunable by controlling the feeding amount of monomers in each synthetic step. The pore size of PPy nanocapsules was controllable from 19 to 33 nm by changing the monomer amount from 5.4 to 20.2 mmol in the first synthetic step. The shell thickness also increased gradually from 5.0 to 12.5 nm with increasing the feeding amount of monomers from 14.9 to 48.5 mmol in the second synthetic step. The average diameter of polymer nanocapsules could also be controllable by changing the surfactant concentration and surfactant spacer length. PPy nanocapsules had two mesopores, that is, the inner cavity and the mesochannel in the wall. In addition, PPy hollow nanospheres could be transformed into carbon nanocapsules through the carbonization process. The structural development of graphene layers in the carbon nanocapsule wall was investigated using XRD measurement, Raman spectroscopy, and HRTEM analysis. The ability to selectively encapsulate and release guest molecules was examined by introducing a photochromic dye (pyrene) solution into the polymer and carbon nanocapsules in a different environment

Morphogenesis and Optoelectronic Properties of Supramolecular Assemblies of Chiral Perylene Diimides in a Binary Solvent System

1131Ysciescopu

Observation of orientation-dependent photovoltaic behaviors in aligned organic nanowires

We fabricated organic nanowire (NW) solar cells based on aligned NWs of n-channel organic semiconductor, N,N???-bis(2-phenylethyl)-perylene-3,4:9, 10-tetracarboxylic diimide via a filtration-and-transfer alignment method. It is well known that most efficient charge transport typically takes place along the long axis of organic NWs. However, there is no systematic study on the correlation between the orientation of NWs in the active layer and the power conversion efficiency (PCE) of solar cells. Our results demonstrate the effects of alignment direction of NWs on the PCE of organic solar cells with single-crystalline NWs.open0

Chiral self-sorted multifunctional supramolecular biocoordination polymers and their applications in sensors

Chiral supramolecules have great potential for use in chiral recognition, sensing, and catalysis. Particularly, chiral supramolecular biocoordination polymers (SBCPs) provide a versatile platform for characterizing biorelated processes such as chirality transcription. Here, we selectively synthesize homochiral and heterochiral SBCPs, composed of chiral naphthalene diimide ligands and Zn ions, from enantiomeric and mixed R-ligands and S-ligands, respectively. Notably, we find that the chiral self-sorted SBCPs exhibit multifunctional properties, including photochromic, photoluminescent, photoconductive, and chemiresistive characteristics, thus can be used for various sensors. Specifically, these materials can be used for detecting hazardous amine materials due to the electron transfer from the amine to the SBCP surface and for enantioselectively sensing a chiral species naproxen due to the different binding energies with regard to their chirality. These results provide guidelines for the synthesis of chiral SBCPs and demonstrate their versatility and feasibility for use in various sensors covering photoactive, chemiresistive, and chiral sensors

Complete genome sequence of probiotic Lactobacillus johnsonii 7409N31 isolated from a healthy Hanwoo calf

Lactobacillus johnsonii 7409N31 was isolated from the feces of a healthy 11-day-old Hanwoo calf from a farm in Geochang-gun, Gyeongsangnam-do, Korea. The genome of the strain was completely sequenced using the PacBio RSII sequencing system, and it was confirmed that it was composed of one circular chromosome. The size of the entire genome was 2,198,442 bp, and it had 35.01 mol% guanine + cytosine (G + C) content and 2,222 protein-coding sequences, 24 rRNA, 3 ncRNA, and 112 tRNA genes. Strain 7409N31 possessed genes encoding enzymes involved in the hydrolysis of both fibrous and non-fibrous carbohydrates. These data provide a comprehensive theoretical understanding for developing industrial probiotic feed additives that improve nutrient digestibility