Nanowire-on-Nanowire: All-Nanowire Electronics by On-Demand Selective Integration of Hierarchical Heterogeneous Nanowires

Lee, Habeom,Manorotkul, Wanit,Lee, Jinhwan,Kwon, Jinhyeong,Suh, Young Duk,Paeng, Dongwoo,Grigoropoulos, Costas P.,Han, Seungyong,Hong, Sukjoon,Yeo, Junyeob,Ko, Seung Hwan American Chemical Society 2017 ACS NANO Vol.11 No.12

<P>Exploration of the electronics solely composed of bottom-up synthesized nanowires has been largely limited due to the complex multistep integration of diverse nanowires. We report a single-step, selective, direct, and on-demand laser synthesis of a hierarchical heterogeneous nanowire-on-nanowire structure (secondary nanowire on the primary backbone nanowire) without using any conventional photolithography or vacuum deposition. The highly confined temperature rise by laser irradiation on the primary backbone metallic nanowire generates a highly localized nanoscale temperature field and photothermal reaction to selectively grow secondary branch nanowires along the backbone nanowire. As a proof-of-concept for an all-nanowire electronics demonstration, an all-nanowire UV sensor was successfully fabricated without using conventional fabrication processes.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2017/ancac3.2017.11.issue-12/acsnano.7b06098/production/images/medium/nn-2017-06098z_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn7b06098'>ACS Electronic Supporting Info</A></P>

Material-Independent Nanotransfer onto a Flexible Substrate Using Mechanical-Interlocking Structure

Seo, Min-Ho,Choi, Seon-Jin,Park, Sang Hyun,Yoo, Jae-Young,Lim, Sung Kyu,Lee, Jae-Shin,Choi, Kwang-Wook,Jo, Min-Seung,Kim, Il-Doo,Yoon, Jun-Bo American Chemical Society 2018 ACS NANO Vol.12 No.5

<P>Nanowire-transfer technology has received much attention thanks to its capability to fabricate high-performance flexible nanodevices with high simplicity and throughput. However, it is still challenging to extend the conventional nanowire-transfer method to the fabrication of a wide range of devices since a chemical-adhesion-based nanowire-transfer mechanism is complex and time-consuming, hindering successful transfer of diverse nanowires made of various materials. Here, we introduce a material-independent mechanical-interlocking-based nanowire-transfer (MINT) method, fabricating ultralong and fully aligned nanowires on a large flexible substrate (2.5 × 2 cm<SUP>2</SUP>) in a highly robust manner. For the material-independent nanotransfer, we developed a mechanics-based nanotransfer method, which employs a dry-removable amorphous carbon (a-C) sacrificial layer between a vacuum-deposited nanowire and the underlying master mold. The controlled etching of the sacrificial layer enables the formation of a mechanical-interlocking structure under the nanowire, facilitating peeling off of the nanowire from the master mold robustly and reliably. Using the developed MINT method, we successfully fabricated various metallic and semiconductor nanowire arrays on flexible substrates. We further demonstrated that the developed method is well suited to the reliable fabrication of highly flexible and high-performance nanoelectronic devices. As examples, a fully aligned gold (Au) microheater array exhibited high bending stability (10<SUP>6</SUP> cycling) and ultrafast (∼220 ms) heating operation up to ∼100 °C. An ultralong Au heater-embedded cuprous-oxide (Cu<SUB>2</SUB>O) nanowire chemical gas sensor showed significantly improved reversible reaction kinetics toward NO<SUB>2</SUB> with 10-fold enhancement in sensitivity at 100 °C.</P> [FIG OMISSION]</BR>

Controllability of Threshold Voltage of ZnO Nanowire Field Effect Transistors by Manipulating Nanowire Diameter by Varying the Catalyst Thickness

Lee, Sang Yeol The Korean Institute of Electrical and Electronic 2013 Transactions on Electrical and Electronic Material Vol.14 No.3

The electrical properties of ZnO nanowire field effect transistors (FETs) have been investigated depending on various diameters of nanowires. The ZnO nanowires were synthesized with an Au catalyst on c-plane $Al_2O_3$ substrates using hot-walled pulsed laser deposition (HW-PLD). The nanowire FETs are fabricated by conventional photo-lithography. The diameter of ZnO nanowires is simply controlled by changing the thickness of the Au catalyst metal, which is confirmed by FE-SEM. It has been clearly observed that the ZnO nanowires showed different diameters simply depending on the thickness of the Au catalyst. As the diameter of ZnO nanowires increased, the threshold voltage of ZnO nanowires shifted to the negative direction systematically. The results are attributed to the difference of conductive layer in the nanowires with different diameters of nanowires, which is simply controlled by changing the catalyst thickness. The results show the possibility for the simple method of the fabrication of nanowire logic circuits using enhanced and depleted mode.

실버 나노와이어의 합성 및 폴리스티렌/실버 나노와이어 나노복합재료의 물성

이성재 水原大學校 2013 論文集 Vol.27 No.-

Polymer/metallic nanowire nanocomposite is one of the advanced materials by the potential application of emerging nanotechnologies. In particular, silver nanowires with excellent electrical conductivity and high aspect ratio are critical for the preparation of conductive polymer nanocomposites. In this work, highly conductive polystyrene/silver nanowire nanocomposites were prepared and their electrical and rheological properties were investigated. Silver nanowires were synthesized using a polyol method, which is suitable for offering high yield of long and thin nanowires. Suspension of silver nanowires was incorporated with polystyrene solution to produce polymer nanocomposites with nanowire network structure providing electrical pathways. Electrically conductive network of silver nanowires was obtained at the electrical percolation threshold of 0.33 vol% silver nanowire, and the electrical conductivity of 103 S/m was obtained at more than 1.5 vol%. Dynamic rheological properties evaluated at 1 vol% also confirmed that silver nanowires were physically connected to one another at this concentration.

MOCVD 방법에 의한 Si 기판위 GaN 나노선의 성장

우시관,신대근,오병성,이형규,Woo, Shi-Gwan,Shin, Dae-Keun,O, Byung-Sung,Lee, Hyung-Gyoo 한국전기전자재료학회 2010 전기전자재료학회논문지 Vol.23 No.11

We have grown GaN nanowires by the low pressure MOCVD method on Ni deposited oxidized Si surface and have established optimum conditions by observing surface microstructure and its photoluminescence. Optimum growth temperature of $880^{\circ}C$, growth time of 30 min, TMG source flow rate of 10 sccm have resulted in dense nanowires on the surface, however further increase of growth time or TMG flow rate has not increased the length of nanowire but has formed nanocrystals. On the contrary, the increase of ammonia flow has increased the length of nanowires and the coverage of nanowire over the surface. The shape of nanowire is needle-like with a Ni droplet at its tip; the length is tens of micron with more than 40 nm in diameter. Low temperature photoluminescence obtained from the sample at optimum growth condition has revealed several peaks related to exciton decay near band-edge, but does not show any characteristic originated from one dimensional quantum confinement. Strong and broad luminescence at 2.2 eV is observed from dense nanowire samples and this suggests that the broad band is related to e-h recombination at the surface state in a nanowire. The current result is implemented to the nanowire device fabrication by nanowire bridging between micro-patterned neighboring Ni catalysis islands.

Hydroxypropyl methylcellulose 접착력 증진제 첨가에 따른 은 나노와이어 용액 및 필름의 특성 변화

정진욱,김종복 한국접착및계면학회 2023 접착 및 계면 Vol.24 No.2

Silver nanowire-based transparent electrodes are very attractive as a next-generation flexible and transparent electrode that can replace ITO-based flexible electrodes because they have excellent conductivity, transmittance and mechanical flexibility. However, weak understanding of the silver nanowire solution for the fabrication of silver nanowire-based transparent electrodes often cause abnormal operation of the electrical device or peeling problem of the electrode films when applied to electronic devices. Here, we studied a Hydroxypropyl Methylcellulose (HPMC) adhesion promoter, which is one of the additives for silver nanowire solution, to improve the understanding of silver nanowire solution. In detail, it is characterized how the HPMC changes the properties of silver nanowire solution and silver nanowire film, which is fabricated with silver nanowire solution including the HPMC adhesion promoter. As the characteristics of solution, polar surface tension and dispersive surface tension were measured. As the film characteristics, surface energy, surface morphology, silver nanowire density, and sheet resistance were analyzed.

Controllability of Threshold Voltage of ZnO Nanowire Field Effect Transistors by Manipulating Nanowire Diameter by Varying the Catalyst Thickness

이상렬 한국전기전자재료학회 2013 Transactions on Electrical and Electronic Material Vol.14 No.3

The electrical properties of ZnO nanowire field effect transistors (FETs) have been investigated depending on various diameters of nanowires. The ZnO nanowires were synthesized with an Au catalyst on c-plane Al2O3 substrates using hot-walled pulsed laser deposition (HW-PLD). The nanowire FETs are fabricated by conventional photo-lithography. The diameter of ZnO nanowires is simply controlled by changing the thickness of the Au catalyst metal, which is confirmed by FE-SEM. It has been clearly observed that the ZnO nanowires showed different diameters simply depending on the thickness of the Au catalyst. As the diameter of ZnO nanowires increased, the threshold voltage of ZnO nanowires shifted to the negative direction systematically. The results are attributed to the difference of conductive layer in the nanowires with different diameters of nanowires, which is simply controlled by changing the catalyst thickness. The results show the possibility for the simple method of the fabrication of nanowire logic circuits using enhanced and depleted mode.

압축-인장 하중을 받는 구리 나노와이어의 비탄성 거동에 대한 연구

이상진(Sangjin Lee),조맹효(Maenghyo Cho) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.5

Deformation mechanism of nanowire is determined by the orientation of nanowire and external loading condition. In the case of 〈100〉/{100} copper nanowire, slip occurs on tensile loading while twinning occurs on compressive loading. Deformed parts of nanowire by twinning recover under tensile loading and 〈100〉/{100} copper nanowire exhibits pseudoelasticity behavior during cyclic loading. The reversibility of twinning is a key factor for pseudoelasticity of 〈100〉/{I00} copper nanowire. But, when a nanowire is compressed over critical strain value, twins encounter each other and partly make abnormal structure. Then, slip occurs under tensile loading and the nanowire never recovers initial state. The critical strain decides inelastic behavior of 〈100〉/{100} copper nanowire under compression-tension.

A facile fabrication of n-type Bi₂Te₃ nanowire/graphene layer-by-layer hybrid structures and their improved thermoelectric performance

Ju, Hyun,Kim, Myeongjin,Kim, Jooheon Elsevier 2015 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.275 No.-

<P><B>Abstract</B></P> <P>n-Type Bi<SUB>2</SUB>Te<SUB>3</SUB> nanowire/graphene composite films were prepared with a facile wet chemical synthesis and sintering process, and the effect of Bi<SUB>2</SUB>Te<SUB>3</SUB> nanowire content on the thermoelectric properties of the composite films were investigated. The one-dimensional Bi<SUB>2</SUB>Te<SUB>3</SUB> nanowires were homogeneously intercalated and dispersed between the prepared graphene layers, forming the Bi<SUB>2</SUB>Te<SUB>3</SUB> nanowire/graphene layer-by-layer hybrid structure. These composite films showed enhanced thermoelectric properties compared to the pristine graphene film fabricated with the same methods but without the Bi<SUB>2</SUB>Te<SUB>3</SUB> nanowires. This was attributed to both the large Seebeck coefficient, which is intrinsic to the Bi<SUB>2</SUB>Te<SUB>3</SUB> nanowires, and the reduced thermal conductivity, which is attributed to the exceptional phonon scattering at the interfaces between the nanowires and graphene layers. The maximum thermoelectric efficiency (<I>ZT</I>) of the Bi<SUB>2</SUB>Te<SUB>3</SUB> nanowire/graphene composites was achieved with a Bi<SUB>2</SUB>Te<SUB>3</SUB> nanowire content of 20wt.%. This composite had a dramatically improved <I>ZT</I> value of 0.2, which was ∼27 times larger than that of the pristine graphene film.</P> <P><B>Highlights</B></P> <P> <UL> <LI> n-Type Bi<SUB>2</SUB>Te<SUB>3</SUB> nanowire/graphene layer-by-layer composites are fabricated. </LI> <LI> Synthesized composite films show high thermoelectric performance. </LI> <LI> Bi<SUB>2</SUB>Te<SUB>3</SUB> nanowires contribute to the increase in Seebeck coefficient of the composite. </LI> <LI> Phonons are significantly scattered at the interfaces between nanowires and graphene. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

수열합성법을 이용한 망간 나노와이어 제조 및 이의 전기화학적 특성 연구

홍석복 ( Seok Bok Hong ),강온유 ( On Yu Kang ),황성연 ( Sung Yeon Hwang ),허영민 ( Young Min Heo ),김정원 ( Jung Won Kim ),최봉길 ( Bong Gill Choi ) 한국공업화학회 2016 공업화학 Vol.27 No.6

본 연구에서는 1차원의 MnO₂ nanowire를 KMnO₄와 MnSO₄ 전구체 혼합물의 수열합성법(hydrothermal method)을 사용하여 제조할 수 있는 합성법을 개발하였다. 제조된 MnO₂ nanowire는 전기화학 반응 동안 전자와 이온전달을 용이하게 할 수 있는 넓은 비표면적과 기공구조를 나타내었다. MnO₂ nanowire의 미세구조 및 화학구조를 주사형 전자현미경(SEM), 투과전자현미경(TEM), 광전자분석기(XPS), X-ray 회절분석법(XRD), 비표면적분석장비(BET)를 사용하여 분석하였다. 본 MnO₂ nanowire 전극의 전기화학적 특성은 순환전압전류법(cyclic voltammetry)과 정전류 충전-방전법(galvanostatic charge-discharge)을 사용하여 3상 전극 시스템(three-electrode system)에서 분석하였다. MnO₂ nanowire 전극은 높은 비정전용량(129 F/g), 고속 충방전(61% retention), 반 영구적인 수명특성(100%)을 나타내었다. In this work, we developed a synthetic method for preparing one-dimensional MnO₂ nanowires through a hydrothermal meth-od using a mixture of KMnO₄ and MnSO₄ precursors. As-prepared MnO₂ nanowires had a high surface area and porous struc-ture, which are beneficial to the fast electron and ion transfer during electrochemical reaction. The microstructure and chemical structure of MnO₂ nanowires were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and Brunauer-Emmett-Teller measurements. The electrochemical properties of MnO₂ nanowire electrodes were also investigated using cyclic voltammetry and galvanostatic charge-discharge with a three-electrode system. MnO₂ nanowire electrodes showed a high specific capacitance of 129 F/g, a high rate capability of 61% retention, and an excellent cycle life of 100% during 1000 cycles.