• Carbon letters
• /
• v.12 no.4
• /
• pp.194-206
• /
• 2011

Carbon nanomaterials in organic photovoltaic (OPV) cells have attracted a great deal of interest for the development of high-efficiency, flexible, and low-cost solar cells. Due to the complicated structure of OPV devices, the electrical properties and dispersion behavior of the carbon nanomaterials should be controlled carefully in order for them to be used as materials in OPV devices. In this paper, a fundamental theory of the electrical properties and dispersion behavior of carbon nanomaterials is reviewed. Based on this review, a state-of-the-art OPV device composed of carbon nanomaterials, along with issues related to such devices, are discussed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.8
• /
• pp.812-822
• /
• 2004

This paper shows that carbon nanotubes can be applied to a nanopipette. Nano space in atomic force microscope multi-wall carbon nanotube tips is filled with molecules and atoms with charges and then, the tips can be applied to nanopipette when the encapsulated media flow off under applying electrostatic forces. Since the nano space inside the tips can be refilled, the tips can be permanently used in ideal conditions of no chemical reaction and no mechanical deformation. Molecular dynamics simulations for nanopipette applications demonstrated the possibility of nano-lithography or single-metallofullerene-transistor array fabrication.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.164.1-164.1
• /
• 2014

플러렌은 구조적인 특성때문에 흡착된 표면의 재료적 성질과 구조 그리고 흡착 배향에 따라 전자구조가 민감하게 변한다. 그래핀 위의 플러렌은 약한 van der Waals interaction으로 인해 매우 균일한 패턴으로 자가조립하여 decoupling 되는 것으로 알려져 있지만 [1,2] 그래핀을 지지하는 substrate의 종류에 따라 플러렌의 전자 구조에 영향을 미치는 것으로 보인다 [3]. 우리는 substrate에 의한 효과를 관찰하기 위헤 Cu(111)위에 그래핀과 플러렌을 순차적으로 성장시켜 STM을 이용하여 플러렌의 흡착구조 및 전자 구조를 연구하였다. 플러렌과 그래핀 사이의 van der Waals interaction과 이웃한 플러렌 분자들 사이의 intermolecular interaction 세기에 따라 흡착 구조가 크게 영향을 받음을 알 수 있었다.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.190.2-190.2
• /
• 2014

We report the origin of the improvement of the power conversion efficiency (PCE) of hybrid thin-film solar cells when a soluble C60 derivative, [6,6]-phenyl-$C_{61}$-butyric acid methyl ester (PCBM), is introduced as a hole-blocking layer. The PCBM layer could establish better interfacial contact by decreasing the reverse ark-saturation current density, resulting in a decrease in the probability of carrier recombination. The power conversion efficiency of this optimized device reached a maximum value of 8.34% and is the highest yet reported for hybrid thin-film solar cells.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2014.11a
• /
• pp.150-150
• /
• 2014

지구상 존재하는 화석연료의 고갈에 대한 우려와 함께 최근 들어 지구 온난화로 인해 야기되고 있는 심각한 지구환경 문제에 대한 관심이 고조되고 있다. 이산화탄소로 대표되는 지구 온난화를 일으키는 공해물질의 많은 부분이 현재 주에너지원으로 사용되는 화석연료에 기인하기 때문에 이를 대체할 수 있는 청정에너지 개발은 이미 세계적 당면 과제라고 할 수 있다. 그 중, 수소에너지는 청정에너지로써의 역할 뿐만 아니라 에너지 저장매체로써의 기능 또한 담당할 수 있어 주목 받고 있다. 본 연구에서는 텅스텐 광촉매를 사용하여 물을 수소와 산소로 분해 하고자 하였고 C70을 도입하여 분해 효율을 향상시키고자 하였다.

• Carbon letters
• /
• v.4 no.4
• /
• pp.175-179
• /
• 2003

It is well established that halogenated fullerene derivatives act as synthetic intermediates for further substitution via replacement with nucleophlies. In the present work, systematic studies were carried out on the synthesis of bromofullerenes under different experimental conditions. The effect of reaction time on the product formed was observed. We observed the formation of new compound of bromofullerenes in a different stoichiometric ratio i.e., $C_{60}Br_{14}$; in addition to previous reported bromofullerenes in the stoichiometric ratio of $C_{60}Br_6$, $C_{60}Br_8$, and $C_{60}Br_{24}$. The new derivative of bromofullerene was isolated and well characterized by various analytical techniques like FT-IR, TGA, DSC, and elemental analysis. In this paper, detail of the synthesis and characterization of the bromofullerene prepared are described. The yields obtained were better than those reported previously.

• Proceedings of the Optical Society of Korea Conference
• /
• 1995.06a
• /
• pp.161-168
• /
• 1995

Nonlinear optical absorption in solid films of poly(3-octyl thiophene) (P3OT) sensitized with methanofullerene was inverstigated for wacelengths from 620 to 960nm. The nonlinear absorption is ehnanced over that in either of the component materials by more than two orders orders of magitude at 760nm. The large nonlinearity results from effient photoinduced interm olecular charge transfer from P3OT to methanofullerene, followed by absorption in the charge separated excited state. P3OT/fullerene films are promising as reverse saturable absorbers and the optical limiting performance is demonstrated at 760nm.

• Elastomers and Composites
• /
• v.53 no.2
• /
• pp.75-79
• /
• 2018

ZnS:Mn-glycine (ZnS:Mn-Gly) nanocomposites were synthesized by capping ZnS:Mn nanocomposites with glycine. Zinc sulfate heptahydrate ($ZnSO_4{\cdot}7H_2O$), glycine ($C_2H_5NO_2$), manganese sulfate monohydrate ($MnSO_4{\cdot}H_2O$), and sodium sulfide ($Na_2S$) were used as the source reagents. $ZnS:Mn-Gly-C_{60}$ nanocomposites were obtained by heating the ZnS:Mn-Gly nanocomposites and fullerene ($C_{60}$) at a 2:1 mass ratio in an electric furnace at $700^{\circ}C$ for 2 h. X-ray diffraction (XRD) was used to characterize the crystal structure of the synthesized nanocomposites. The photocatalytic activity of the $ZnS:Mn-Gly-C_{60}$ nanocomposites was evaluated, via the degradation of brilliant green (BG) dye under 254 nm irradiation, with a UV-vis spectrophotometer.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.21 no.2
• /
• pp.118-125
• /
• 2008

Single walled carbon nanotubes (SWCNTs) can be modified to produce a new concept of hybrid materials by introducing atoms or molecules inside their cylindrical empty space. Such an endohedral doping of the SWCNTs is expected to decisively alter their electronic transport and mechanical properties, In this study, we purified SWCNTs by three-step purification processes and formed the peapod structure by introducing $C_{60}$ fullerenes inside the SWCNTs. $C_{60}$ molecules were observed to be regularly arranged by transmission electron microscopy. In Raman spectra, the radial breathing mode (RBM) rather than the other modes was significantly affected by the endohedral injection of $C_{60}$. The RBM intensity was more greatly reduced in the large-diameter SWCNTs than the small-diameter ones, Raman spectroscopy is expected to be a key technique for analyzing $C_{60}$-encapsulated SWCNTs.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.19 no.3
• /
• pp.319-329
• /
• 2016

Current research trends of prediction of possible structures, synthesis and explosive characteristics of polynitrogen molecules(PNs) are reviewed. Theoretically PNs are composed only of nitrogen atoms, in which N-N bonds are either single or double bonds, and thus when these molecules decompose, release of enormous energy is accompanied. From the middle of 20th century energetic material chemists have been seeking possible structures and the methods of synthesis of these new materials. As a results, from $N_4$ to $N_{60}$ together with their ions are predicted, and experimental chemists have been trying to synthesize these materials with a few success, including the famous ${N_5}^+$ ion in 1999. Although experimental successes are very rare beyond $N_5$ until today, the author believes that renovative ideas together with sincere efforts will bring someday next generation of high energy materials such as nitrogen fullerene($N_{60}$) in reality.