• 한국전기전자재료학회논문지
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• 제35권5호
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• pp.439-444
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• 2022

Laser-induced plasmonic sintering of metal nanoparticles (NPs) is a promising technology to fabricate flexible conducting electrodes, since it provides instantaneous, simple, and scalable manufacturing strategies without requiring costly facilities and complex processes. However, the metal NPs are quite expensive because complicated synthesis procedures are needed to achieve long-term reliability with regard to chemical deterioration and NP aggregation. Herein, we report laser-induced Ag NP self-generation and sequential sintering process based on low-cost Ag organometallic material for demonstrating high-quality microelectrodes. Upon the irradiation of laser with 532 nm wavelength, pre-baked Ag organometallic film coated on a transparent polyimide substrate was transformed into a high-performance Ag conductor (resistivity of 2.2 × 10^-4 Ω·cm). To verify the practical usefulness of the technology, we successfully demonstrated a wearable transparent heater by using Ag-mesh transparent electrodes, which exhibited a high transmittance of 80% and low sheet resistance of 7 Ω/square.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2017년도 춘계학술대회 논문집
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• pp.123.1-123.1
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• 2017

Hybrid solar cells have intensively studied in recent years due to their advantages such as cost effectiveness and possibility of applications in flexible and transparent devices. It is critical to fabricate individual layer composed of organic and inorganic materials in the hybrid solar cell at low cost. Therefore, it is required to manufacture cheaply and enhance the photon-to-electricity conversion efficiency of each layer in the flexible solar cell industry. In this research, we fabricated pure Cu metal mesh electrode prepared by using electroplating and/or electroless plating on the Ni mold which was manufacture through photolithography, electroforming, and polishing process. Copper mesh was formed on the surface of nickel metal working master when pulsed electrolytic copper deposition were performed at various plating parameters such as plating time, current density, and so on. After electrodeposition at 2ASD for 5~30seconds, the line/pitch/thickness of copper mesh sheet was $1.8{\sim}2.0/298/0.5{\mu}m$.

• 한국정밀공학회지
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• 제27권9호
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• pp.11-15
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• 2010

In this study, to fabricate a low-resistance and high optical transparency electrode film, the following steps were performed: the design and manufacture of electroforming stamp, the fabrication of a thermal roll-imprinted polycarbonate (PC) patterned films, the filled low-resistance Ag paste using doctor blade process on patterned PC films and spin coating by conductive polymers. As a result of PC films imprinted line width of $26.69{\pm}2\;{\mu}m$, channel length of $247.57{\pm}2\;{\mu}m$, and pattern depth of $7.54{\pm}0.2\;{\mu}m$. Ag paste to fill part of the patterned film with conductive polymer coating and then the following parameters were obtained: a sheet resistance of $11.1\;{\Omega}/sq$ optical transparency values at a wavelength of 550 nm was 80.31 %.

• 한국재료학회지
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• 제30권3호
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• pp.131-135
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• 2020

Silver nanowire (AgNW) networks have been adopted as a front electrode in Cu(In,Ga)Se2 (CIGS) thin film solar cells due to their low cost and compatibility with the solution process. When an AgNW network is applied to a CIGS thin film solar cell, reflection loss can increase because the CdS layer, with a relatively high refractive index (n ~ 2.5 at 550 nm), is exposed to air. To resolve the issue, we apply solution-processed ZnO nanorods to the AgNW network as an anti-reflective coating. To obtain high performance of the optical and electrical properties of the ZnO nanorod and AgNW network composite, we optimize the process parameters - the spin coating of AgNWs and the concentration of zinc nitrate and hexamethylene tetramine (HMT - to fabricate ZnO nanorods. We verify that 10 mM of zinc nitrate and HMT show the lowest reflectance and 10% cell efficiency increase when applied to CIGS thin film solar cells.

• 반도체디스플레이기술학회지
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• 제19권3호
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• pp.36-42
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• 2020

Silver nanowire (AgNW) random-meshes with high transmittance, low sheet resistance, and high oxidation stability and flexibility were fabricated using solution-based processes. The random-mesh structure was obtained by forming bubbles whose sizes and densities were controlled using a corona treatment of polyethylene terephthalate (PET) substrates. To reduce the sheet resistance of the fabricated AgNW electrode, a washing process using ethanol solution was performed. In addition, nickel (Ni) was coated on AgNW to improve resistance to oxidation. The effects of corona treatment and Ni-coating on the transmittance, sheet resistance, oxidation stability, and flexibility of the AgNW electrodes were investigated.

• 한국분말재료학회지
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• 제24권6호
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• pp.464-471
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• 2017

A metal mesh TCE film is fabricated using a series of processes such as UV imprinting of a transparent trench pattern (with a width of $2-5{\mu}m$) onto a PET film, filling it with silver paste, wiping of the surface, and heat-curing the silver paste. In this work nanosized (40-50 nm) silver particles are synthesized and mixed with submicron (250-300 nm)-sized silver particles to prepare silver paste for the fabrication of metal mesh-type TCE films. The filling of these silver pastes into the patterned trench layer is examined using a specially designed filling machine and the rheological testing of the silver pastes. The wiping of the trench layer surface to remove any residual silver paste or particles is tested with various mixture solvents, and ethyl cellosolve acetate (ECA):DI water = 90:10 wt% is found to give the best result. The silver paste with 40-50 nm Ag:250-300 nm Ag in a 10:90 wt% mixture gives the highest electrical conductance. The metal mesh TCE film obtained with this silver paste in an optimized process exhibits a light transmittance of 90.4% and haze at 1.2%, which is suitable for TSP application.

• Current Photovoltaic Research
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• 제2권1호
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• pp.14-17
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• 2014

In this paper, indium reduced materials for transparent conductive electrodes (TCE) were fabricated and their physical properties were evaluated. Two of materials, indium-zinc-tin oxide (IZTO) and aluminum (Al) were selected as TCE materials. In case of IZTO nanoparticles, composition ratios of In, Zn and Sn is 8:1:1 were synthesized. Size of the synthesized IZTO nanoparticles were less than 10 nm, and specific surface areas were about $90m^2/g$ indicating particle sizes are very fine. Also, the IZTO nanoparticles were well crystallized with (222) preferred orientation despite it was synthesized at the lowered temperature of $300^{\circ}C$. Composition ratios of In, Zn and Sn were very uniform in accordance with those as designed. Meanwhile, Al was deposited onto glass by sputtering in a vacuum chamber for mesh architecture. The Al was well deposited onto the glass, and no pore was observed from the Al surface. The sheet resistance of Al on glass was about $0.3{\Omega}/{\square}$ with small deviation of $0.025{\Omega}/{\square}$, and adhesion was good on the glass substrate since no pelt-off part of Al was observed by tape test. If the Al mesh is combined with ink coated layer which is consistent of IZTO nanoparticles, it is expected that the good and reliable metal mesh architecture for TCE will be formed.

• 한국전자파학회논문지
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• 제29권7호
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• pp.477-483
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• 2018

본 논문에서는 FM 방송대역(88~108 MHz)에서 동작하는 자동차 전면 글래스 상에 설계되는 투명 안테나를 제안한다. 투명 안테나는 전형적으로 차량 지붕에 설치된 샤크핀 안테나의 공간적 제한을 피하기 위해 차량 전면 글래스에 구현하였다. 전면 글래스에 설계되는 안테나는 낮은 수심감도와 다른 서비스대역의 안테나로부터의 방사간섭 문제를 합리적으로 해결할 수 있다. 전면 글래스는 고유한 closed-line 구조를 가지고 있으며, 이 구조로 인해 전면 글래스 외곽의 차체 표면으로 전류가 흐르게 되어 FM 방송대역 이전 부분에서 첫 공진점이 발생한다. Closed-line 구조를 이용한 표면 전류 길이 제어를 통해 첫 공진점이 FM 대역에서 동작하는 안테나를 설계하였다. 또한, RF 수동소자로 설계하기 적합한 투명전극 소자 마이크로 메탈메쉬 필름의 투명성을 통해 시각적 인식의 최소화 하였다. 측정된 안테나는 FM 대역에서 반사계수는 -6 dB 이하이며, average peak gain은 -0.9 dB이다. 본 연구를 통해 제안된 전면 글래스 투명안테나는 미래의 자동차 안테나 개발에 필요한 공간과 설계 자유에 대한 가능성을 보여주었다.

• 대한기계학회논문집B
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• 제36권10호
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• pp.1011-1017
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• 2012

본 논문에서는 롤타입 마스크를 사용한 마이크로/나노 구조 제작용 광학 리소그래피 방법을 소개한다. 이 생산 방법은 다양한 목표 해상도에 따라 위상지연 리소그래피방법과 포토리소그래피로 나뉜다. 사용되는 빛의 파장대보다 작은 해상도를 갖는 패턴을 제작하기 위해서 실린더 형태의 위상지연 마스크를 활용한 근거리 노광 방식을 사용한다. 또한 필름 형태의 금속 마스크를 써서 포토리소그래피를 연속방식으로 수행하였는데 이 방식은 실린더 마스크의 회전수를 조절함으로써 노광 결과 패턴의 주기를 실시간으로 조절할 수 있다. 이 기술의 응용으로 금속 그물패턴으로 만들어진 100 $mm^2$ 넓이의 투명전극을 제작하였다.

• 한국산학기술학회논문지
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• 제11권10호
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• pp.3853-3858
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• 2010

본 논문에서는 메디치 프로그램을 사용하여 반사방지막(ARC : anti reflectance coating) 두께에 따라 실리콘 솔라셀의 전기적 특성분석을 보여준다. ITO 투명전극으로 이루어지는 ARC를 이용한 실리콘 솔라셀의 메쉬구조를 구축하고 ARC 두께에 따른 특성해석 모델링을 실시하였다. ARC 산화층의 두께가 30 nm, 60 nm. 90 nm일 때 입사광의 파장에 따른 외부 수집 효율성, 투과율, Isc, Voc, I-V 특성 변화 등을 구하였다. 시뮬레이션 결과 60 nm의 반사방지막 두께에서 최대전력 22 mW/$cm^2$, 0.83의 곡선 인자를 보였다.