• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.266.1-266.1
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• 2013

Large-scale single-crystal organic nanowire arrays were generated 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. Repeated application of the direct printing process can be used to produce organic nanowire-integrated electronics with two- or 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.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.361.2-361.2
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• 2016

The manufacture of organic electronic circuits requires effective heterogeneous integration of different nanoscale organic materials with uniform morphology and crystallinity in a desired arrangement on a substrate. Herein, we present a new direct printing method, which enables monolithic integration of crystalline nanowire arrays with a diverse range of organic materials. In this method, we use a nanoscale patterned soft mold, which contains an assembly of simple nanoline patterns but, in combination with droplet of various organic inks, can produce a large-scale integration of various nanopatterns with multiple kinds of organic materials. The morphology of organic nanowires can controlled by nanoconfinement in nanoline of mold. And mutual alignment of nanopatterns can be controlled by adjusting the ink droplet size, number of droplets, ink deposition locations.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.144.1-144.1
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• 2016

We fabricate organic single crystal nanowire heterojunction p-n diode poly(3-hexylthiophene)(P3HT) and from Phenyl-C61-butyric acid methyl ester(PCBM) using by liquid-bridge mediated nanotransfer molding(LB-nTM) method. LB-nTM has been reported an one step direct printing method for making well-aligned nanowire arrays. Moreover, multi-patterning nanostructures can be fabricated with the consecutive printing process. As a result, it is possible to make simple and basic concept of heterojunction devices such as lateral organic p-n nanojunction diode. P3HT/PCBM nanowires heterojunction diode has rectifying behavior with on/off ratios of ~20.

• 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 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.158-158
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• 2011

A wide range of techniques for the direct-printing of functional materials have been developed for the fabrication of micro- and nanoscale structures and devices. Here we report a new direct patterning method, liquid bridge-mediated nanotransfer molding (LB-nTM), for the formation of two- or three-dimensional structures with feature sized as small as tens of nanometers over large areas up to 4". LB-nTM is based on the direct transfer of various materials from a mold to a substrate via a liquid bridge between them. The LB-nTM method was applied to the preparation of organic nanowire FETs on flexible substrates.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.261.1-261.1
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• 2013

Well-aligned nanowire arrays can be used as building blocks for nanoscale device. Recently, we reported that well-aligned single-crystal organic nanowires has been created by using a direct printing method which is named liquid-bridge mediated nanotransfer molding (LB-nTM). Moreover, multi-layering nanostructures can be fabricated by repeating this printing process. As a result, it is possible to make simple and basic concept of heterojunction devices such as crossed nanowire devices. We fabricated crossed single-crystal organic nanowires nanojunction devices from 6,13-bis (triisopropylsilylethynyl) pentacene (TIPS-PEN) and fullerene (C60) single-crystal nanowires using by direct printing method in solution process. Crossed TIPSPEN/ C60 single-crystal nanowires diode has rectifying behavior with on/off ratios of ~13. In addition, the device shows photodiode characteristics as well as rectification. Our study represent methodology of heterojunction devices using single-crystal nanowires, thereby provide a new direction of future nanoelectronics.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.287-287
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• 2010

We report a new direct patterning method, called liquid bridge-mediated nanotransfer molding (LB-nTM), for the formation of two- or three-dimensional structures with feature sizes between tens of nanometers and tens of micron over large areas. LB-nTM is based on the direct transfer of various materials from a mold to a substrate via a liquid bridge between them. This procedure can be adopted for automated direct printing machines that generate patterns of functional materials with a wide range of feature sizes on diverse substrates. Arrays of TIPS-PEN TFTs were fabricated on 4" polyethersulfone (PES) substrates by LB-nTM using PDMS molds. An inverted staggered structure was employed in the TFT device fabrication. A 150 nm-thick indium-tin oxide (ITO) gate electrode and a 200 nm-thick SiO2dielectric layer were formed on a PES substrate by sputter deposition. An array of TIPS-PEN patterns (thickness: 60 nm) as active channel layers was fabricated on the substrate by LB-nTM. The nominal channel length of the TIPS-PEN TFT was 10 mm, while the channel width was 135 mm. Finally, the source and drain electrodes of 200 nm-thick Ag were defined on the substrate by LB-nTM. The TIPS-PEN TFTs can endure strenuous bending and are also transparent in the visible range, and therefore potentially useful for flexible and invisible electronics.

• 한국전기전자재료학회논문지
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• 제31권7호
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• pp.510-514
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• 2018

This study discusses and demonstrates the structural stability of highly ordered Pt patterns formed on a transparent and flexible substrate through the process of nanotransfer printing (nTP). Bending tests comprising approximately 1,000 cycles were conducted for observing Pt line patterns with a width of $1{\mu}m$ formed along the direction of the horizontal (x-axis) and vertical (y-axis) axes ($15mm{\times}15mm$); and adhesion tests were performed with an ultrasonicator for a period greater than ten minutes, to analyze the Pt crossbar patterns. The durability of both types of patterns was systematically analyzed by employing various microscopes. The results show that the Pt line and Pt crossbar patterns obtained through nTP are structurally stable and do not exhibit any cracks, breaks, or damages. These results corroborate that nTP is a promising nanotechnology that can be applied to flexible electronic devices. Furthermore, the multiple patterns obtained through nTP can improve the working performance of flexible devices by providing excellent structural stability.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.560-560
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• 2012

We report a one-step fabrication method of Poly(9,9-dioctylfluorene) (PFO) nanowire array with pronounced ${\beta}$-Phase. We use liquid-bridge-mediated nanotransfer molding (LB-nTM) which is a new direct nano-patterning method based on the direct transfer of various materials from a mold to a substrate via liquid layer. The formation of the ${\beta}$-phase morphology in the resulting PFO nanowire array was evidenced by the presence of an absorption peak at 435nm. With the collection polarizer oriented parallel to the wire long axis, the PL emission was most intense and an emission dichroic ratio, DRE, of 3.7 was determined. The nanowire array have been investigated by scanning electron microscopy (SEM). Also, we simply fabricated structure of device of ITO/PFO nanowire arrays/Al and the electroluminescence spectra were recorded at various applied voltage.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.108-109
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• 2012

This talk will begin with the demonstration of facile synthesis of silicon nanostructures using the magnesiothermic reduction on silica nanostructures prepared via self-assembly, which will be followed by the characterization results of their performance for energy storage. This talk will also report the fabrication and characterization of highly porous, stretchable, and conductive polymer nanocomposites embedded with carbon nanotubes (CNTs) for application in flexible lithium-ion batteries. It will be presented that the porous CNT-embedded PDMS nanocomposites are capable of good electrochemical performance with mechanical flexibility, suggesting these nanocomposites could be outstanding anode candidates for use in flexible lithium-ion batteries. Directed self-assembly (DSA) of block copolymers (BCPs) can generate uniform and periodic patterns within guiding templates, and has been one of the promising nanofabrication methodologies for resolving the resolution limit of optical lithography. BCP self-assembly processing is scalable and of low cost, and is well-suited for integration with existing semiconductor manufacturing techniques. This talk will introduce recent research results (of my research group) on the self-assembly of Si-containing block copolymers for the achievement of sub-10 nm resolution, fast pattern generation, transfer-printing capability onto nonplanar substrates, and device applications for nonvolatile memories. An extraordinarily facile nanofabrication approach that enables sub-10 nm resolutions through the synergic combination of nanotransfer printing (nTP) and DSA of block copolymers is also introduced. This simple printing method can be applied on oxides, metals, polymers, and non-planar substrates without pretreatments. This talk will also report the direct formation of ordered memristor nanostructures on metal and graphene electrodes by the self-assembly of Si-containing BCPs. This approach offers a practical pathway to fabricate high-density resistive memory devices without using high-cost lithography and pattern-transfer processes. Finally, this talk will present a novel approach that can relieve the power consumption issue of phase-change memories by incorporating a thin $SiO_x$ layer formed by BCP self-assembly, which locally blocks the contact between a heater electrode and a phase-change material and reduces the phase-change volume. The writing current decreases by 5 times (corresponding to a power reduction of 1/20) as the occupying area fraction of $SiO_x$ nanostructures varies.