• 한국세라믹학회지
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• 제41권9호
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• pp.670-676
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• 2004

플라즈마 디스플레이(Plasma Display Panel)의 도전성 전극 성형에 필요한 잉크젯용 은 나노 졸을 합성하고자, 액상 환원법에 의해 고농도의 은 나노 졸의 입자크기 및 입도분포와 분산성을 제어하였다 이를 위하여 생성된 입자에 분산성을 부여하는 고분자 전해질의 착체형성 비율과 함께 은 나노 졸의 고농도화를 진행하였다. 합성된 졸은 XRD, 입도분포측정기, TEM을 사용하여 상분석 및 입자의 크기와 형상을 관찰하였다 그 결과 분산성이 우수하고, 약 10nm의 입자크기를 갖는 은 나노 졸인 것을 확인할 수 있었으며, 10-40wt% 범위의 고농도 은 나노 졸을 합성할 수 있었다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.92-92
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• 2012

Chalcopyrite-type Cu(In,Ga)Se2 (CIGS) is one of the most attractive compound semiconductor materials for thin film solar cells. Among various approaches to prepare the CIGS thin film, the powder process offers an extremely simple and materials-efficient method. Here, we present the mechano-chemical synthesis of CIGS compound powders and their use as an ink material for screen-printing. During the synthesis process, milling time and speed were varied in the range of 10~600 min and 100~300 rpm, respectively. Both phase evolution and powder characteristics were carefully monitored by X-ray diffraction (XRD) method, scanning electron microscope (SEM) observation, and particle size analysis by scanning mobility particle spectrometer (SMPS) and aerodynamic particle sizer (APS). We found the optimal milling condition as 200 rpm for 120 min but also found that a monolithic phase of CIGS powders without severe particle aggregation was difficult to be obtained by the mechano-chemical milling alone. Therefore, the optimized milling condition was combined with an adequate heat-treatment (300oC for 60 min) to provide the monolithic CIGS powder of a single phase with affordable particle characteristics for the preparation of CIGS thin film. The powder was used to prepare an ink for screen printing with which dense CIGS thin films were fabricated under the controlled selenization. The morphology and electrical properties of the thin films were analyzed by SEM images and hall measurement, respectively.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.1.1-1.1
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• 2011

Printed electronics based on the direct writing of solution processable functional materials have been of paramount interest and importance. In this talk, the synthesis of printable inorganic functional materials (conductors and semiconductors) for thin-film transistors (TFTs) and photovoltaic devices, device fabrication based on a printing technique, and specific characteristics of devices are presented. For printable conductor materials, Ag ink is designed to achieve the long-term dispersion stability and good adhesion property on a glass substrate, and Cu ink is sophisticatedly formulated to endow the oxidation stability in air and even aqueous solvent system. The both inks were successfully printed onto either polymer or glass substrate, exhibiting the superior conductivity comparable to that of bulk one. In addition, the organic thin-film transistor based on the printed metal source/drain electrode exhibits the electrical performance comparable to that of a transistor based on a vacuum deposited Au electrode. For printable amorphous oxide semiconductors (AOSs), I introduce the noble ways to resolve the critical problems, a high processing temperature above $400^{\circ}C$ and low mobility of AOSs annealed at a low temperature below $400^{\circ}C$. The dependency of TFT performances on the chemical structure of AOSs is compared and contrasted to clarify which factor should be considered to realize the low temperature annealed, high performance AOSs. For photovoltaic application, CI(G)S nanoparticle ink for solution processable high performance solar cells is presented. By overcoming the critical drawbacks of conventional solution processed CI(G)S absorber layers, the device quality dense CI(G)S layer is obtained, affording 7.3% efficiency CI(G)S photovoltaic device.

• Korean Journal of Chemical Engineering
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• 제35권12호
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• pp.2430-2441
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• 2018

Selenium (Se)-rich binary Cu-Se and In-Se nanoparticles (NPs) were synthesized by a modified heat-up method at low temperature ($110^{\circ}C$) using the gum exudates from a cherry blossom tree. Coating of CISe absorber layer was carried out using Se-rich binary Cu-Se and In-Se NPs ink without the use of any external binder. Our results indicated that the gum used in the synthesis played beneficial roles such as reducing and capping agent. In addition, the gum also served as a natural binder in the coating of CISe absorber layer. The CISe absorber layer was integrated into the solar cell, which showed a power conversion efficiency (PCE) of 0.37%. The possible reasons for low PCE of the present solar cells and the steps needed for further improvement of PCE were discussed. Although the obtained PCE is low, the present strategy opens a new path for the fabrication of eco-friendly CISe NPs solar cell by a relatively chief non-vacuum method.

• 한국결정성장학회지
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• 제24권4호
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• pp.169-175
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• 2014

최근 각광받고 있는 디지털 프린팅을 이용한 디자인 기법은 세밀한 표현과 다양한 이미지 구현이 가능하고, 원료의 낭비가 적어 효율성이 높은 장점을 가지고 있다. 디지털 프린팅 공정에서는 cyan, magenta, yellow, black이 기본적인 디지털 4원색으로 사용되며, 도자제품에 적용되는 세라믹 안료의 경우 $1000^{\circ}C$ 이상의 고온 소성이 가능하도록 우수한 열적, 유약 안정성과 발색 특성이 요구된다. 본 연구에서는 고상합성법을 이용하여 $CaO-SnO_2-Cr_2O_3-SiO_2$ 조성의 pink-red 고온발색 무기안료를 합성하였다. $Ca(Sn,Cr)SiO_5$ 세라믹 안료의 합성 조건에 따른 물성을 XRD, SEM, PSA, FT-IR를 이용하여 분석하였고, Cr 치환량 변화가 $Ca(Sn,Cr)SiO_5$ 무기 안료의 발색 거동에 미치는 영향을 Uv-vis.와 CIE 표색계 값($L^*a^*b^*$)을 기준으로 한 색도측정을 통해 관찰하였다.

• 마이크로전자및패키징학회지
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• 제17권1호
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• pp.33-39
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• 2010

나노잉크를 이용한 프린팅 기술은 기존의 리소그래피를 통한 절연체, 반도체 및 전도체의 패터닝 기술에 비해 비용절감, 대면적 기판 적용 가능성 및 회로의 유연성 등의 측면에서 장점을 가지므로 최근 크게 주목받고 있다. 이러한 프린팅 기술이 반도체 또는 디스플레이 제조 공정에 성공적으로 적용되기 위해서는 먼저 나노입자, 용매 및 첨가제로 구성된 나노잉크 또는 페이스트의 개발이 선행되어야 한다. 본 고에서는 이러한 반도체 및 디스플레이 적용을 위한 나노잉크의 청정 제조기술과 관련하여 최근의 연구 동향에 대하여 보고하고자 한다. 또한 나노잉크의 청정 제조기술과 관련한 구체적인 예를 설명하기 위하여 본 연구팀에서 개발한 청정 저온 $SiO_2$ 합성 기술을 소개하고자 하였다. 먼저 저온에서의 무폐수 청정공정을 통해 $SiO_2$ 나노입자를 제조하고, 이를 이용하여 프린팅 기술에 적용이 가능한 나노잉크를 제조하였다. 제조된 잉크를 유리 기판에 프린팅하여 다양한 특성 평가를 실시하였으며, 마지막으로 제조 공정상의 여러 시험변수가 프린팅된 필름의 전기적 특성에 미치는 영향에 대한 고찰을 통해 기술의 적용가능성을 평가하고자 하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.368-368
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• 2012

We report solution-processed, high-performance single-crystal organic nanowire transistors fabricated from a novel indolocarbazole (IC) derivative. The direct printing process was utilized to generate single-crystal organic nanowire arrays enabling the simultaneous synthesis, alignment and patterning of nanowires using molecular ink solutions. Using this method, single-crystal organic nanowires can easily be synthesized by self-assembly and crystallization of organic molecules within the nanoscale channels of molds, and these nanowires can then be directly transferred to specific positions on substrates to generate nanowire arrays by a direct printing process. These new molecules are particularly suitable for p-channel organic field-effect transistors (OFETs) because of the high level of crystallinity usually found in IC derivatives. Selected area diffraction (SAED) and X-ray diffraction (XRD) experiments on these solution-processed nanowires showed high crystallinity. Transistors fabricated with these nanowires gave a hole mobility as high as 1.0 cm2V-1s-1 with nanowire arrays with the direct printing process.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.563-563
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• 2012

We report a one-step fabrication of single-crystal organic nanowire arrays on substrates using a new direct printing method (liquid-bridge-mediated nanotransfer moulding, LB-nTM), which can simultaneously enable the synthesis, alignment and patterning of the nanowires using molecular ink solutions. Two- or three-dimensional complex structures of various single-crystal organic nanowires were directly fabricated over a large area with a successive process. The position of the nanowires can be aligned easily on complex structures because the mold is movable on substrates before drying the polar liquid layer, which acts as an adhesive lubricant. This efficient manufacturing method can produce a wide range of optoelectronic devices and integrated circuits with single-crystal organic nanowires.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.637-637
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• 2013

We develop single-crystal poly(3,4-ethylenedioxythiopene nanowires using liquid-bridge-mediated nanotransfer printing via vapor phase polymerization. This direct printing method can simultaneously enable the synthesis, alignment and patterning of the nanowires from molecular ink solutions. Twoor three-dimensional complex structures of various single-crystal organic nanowires were directly fabricated over a large area using many types of molecular inks. This method is capable of generating several optoelectronic devices. LB-nTM is based on the direct transfer of various materials from a mold to a substrate via a liquid bridge between them. To demonstrate its usefulness, we used LB-nTM to fabricate nanowire field-effect transistors and arrays of 6,13-bis (triisopropyl- silylethynyl) pentacene (TIPS-PEN) nanowire field-effect transistors.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.632-632
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• 2013

We generated single-crystal organic nanowire arrays using a direct printing method (liquidbridge- mediated nanotransfer molding) that enables the simultaneous synthesis, alignment and patterning of nanowires from molecular ink solutions. Using this method, single-crystal organic nanowires can easily be synthesized by self-assembly and crystallization of organic molecules within the nanoscale channels of molds, and these nanowires can then be directly transferred to specific positions on substrates to generate nanowire arrays by a direct printing process. The position of the nanowires on complex structures is easy to adjust, because the mold is movable on the substrates before the polar liquid layer, which acts as an adhesive lubricant, is dried. Repeated application of the direct printing process can be used to produce organic nanowire-integrated electronics with twoor three-dimensional complex structures on large-area flexible substrates. This efficient manufacturing method is used to fabricate all-organic nanowire field-effect transistors that are integrated into device arrays and inverters on flexible plastic substrates.