저자는 스퍼터 코터 장비에 대한 지원은 XRD 스펙트럼 및 K. Booksh 그의 도움을 Svilen Bobev 감사합니다.

(1)의 합성 트리 모양의 ZnO의 / CdSSe 나노 구조 <ol><li> 사파이어 기판의 전처리 및 골드 코팅 주 : 금막가 된 ZnO 나노 와이어의 성장의 촉매 역할을한다. <ol><li> 초음파 5 분 99.5 % 에탄올 깨끗 슬라이드 사파이어 (a면, 10 × 10 × 1mm)을 금의 스퍼터링 용 기판을 제조 하였다. </li><li> 스퍼터 코터와 골드 대상으로 사파이어 슬라이드에 10 나노 미터 (± 2 ㎚) 금의 두께의 필름을 증착. </li></ol></li><li> 산화 아연 나노 와이어의 합성 주 : 초음파 단계 균질의 ZnO의 1.2.2 결과와 탄소 (ZnO를 / C) 혼합물. 혼합 후, 혼합물은 회색 컬러를 변경한다. 압밀 단계 1.2.3 공기의 혼합물과의 ZnO 및 탄소가 밀착되어 그 존재하지 않는 것을 보장한다. CVD 후, 산화 아연 나노 와이어의 흰색 필름면이 아래 배쪽으로 향, 기판 상에 증착되어야한다. <ol><li> 의 ZnO 나노 분말 및 액티브의 1g을 혼합ated 탄소 (50:50의 질량 분율) 10 ml의 99.5 %의 에탄올과 주걱으로 잘 저어. </li><li> 30 분 동안 20 ºC 수조의 혼합물을 초음파 처리하고 80 ºC에서 ~ 5 시간 동안 오븐에서 건조시킨다. </li><li> 알루미나 보트에서의 ZnO / C 혼합물을 넣고 주걱으로 잘 컴팩트. </li><li> 금 코팅 된면이 아래로 향하게하여, 알루미나 보트의 상단에 골드 코팅 사파이어 슬라이드를 놓습니다. 수평 튜브로의 석영 관의 중심에 알루미나 보트 놓는다. </li><li> 실온에서 40 SCCM (RT)의 유속으로 아르곤으로 1 시간 동안 석영 튜브를 제거. 80 ºC / 분의 속도로 900 ºC RT의 온도를 증가 및 아르곤 유속을 일정하게 유지한다. </li><li> 2 시간 동안 900 ºC의 온도를 잡습니다. 고무 마개 기체 입구를 제거하여 양단에 석영 관을 열고 공기가 반응에 산소를 공급하는 튜브 들어가게. </li><li> RU에 3 시간 동안 900 ºC에서 반응 온도를 유지bber 마개를 제거합니다. 10 ºC / 분의 속도로 실온까지 냉각. </li><li> 보트와 노의 밖으로 슬라이드를 가져 가라. </li></ol></li><li> 산화 아연 나노 와이어에 CdSSe 가지의 증착 주 : CD의 알루미나 보트 / SE는 중앙 석영 관에 표시 하였다. 제조 된 산화 아연 나노 와이어는 위를 향하고 보트에서 10cm 하류이었다 하였다. 이 두 번째 CVD 후, ZnO의 / CdSSe 나노 구조체 인 오렌지 / 옐로우 필름, 슬라이드에 부착해야한다. <ol><li> CD와의 CdSe (CDS / SE) 분말도 (50 : 50의 질량 분율) 0.5 g을 혼합하고 알루미나 보트에 혼합물을 배치합니다. 잘 혼합물을 압축. </li><li> CdS와 / 셀레늄의 알루미나 보트와 석영 관에서 이전에 제조 된 ZnO 나노 와이어 샘플을 놓습니다. </li><li> 1 시간 동안 실온에서 40 sccm의 유량으로 아르곤과 튜브를 제거. 80 ºC / min의 속도로 820 ºC로 반응 온도를 높입니다. 30 분 동안 820 ºC의 온도를 잡습니다. </li><li> 에서 실온까지 냉각10 ºC / 분. 보트와 노의 밖으로 슬라이드를 가져 가라. </li></ol></li><li> 의 ZnO 및 CdSSe 나노 와이어 : 제어 샘플의 합성 <ol><li> 같은 실험 조건 섹션 1.2에서와 같이 산화 아연 나노 와이어를 합성. </li><li> CD와의 CdSe 조성물 동일한 양으로, 동일한 실험 조건 하에서, 1.3 절과 CdSSe 나노 와이어의 합성, 대신에 ZnO를 증착 슬라이드 기판으로서 깨끗하고, 금 - 코팅 된 사파이어 슬라이드. </li></ol></li></ol> 2. 형태 학적 및 결정학 특성 <ol><li> 클램프와 SEM 무대에서 샘플을 탑재하고 SEM 장비의 진공 챔버에서 샘플을 배치합니다. 3 kV의 전압에서의 12.0 mm의 작업 거리, 3,000 및 10000 (11, 12) 사이의 배율 고 해상도 모드의 SEM 이미지를 가라. </li><li> 동일한 작업 거리에서 X 선 검출기를 사용하여 동일한 샘플 EDS 데이터를 받아12.0 mm. 분석 모드로 기기를 설정하고 20-40 μA (13)의 현재의 결과, 20 kV의에 전압을 조정합니다. </li><li> 여과의 Cu Kα 방사선 (λ = 1.5418 Å) (11, 12)를 사용하여 X 선 분말 회절에 XRD 스펙트럼을 수집한다. </li></ol> 3. PL 방출 분광학 및 시간 해결 PL 수명 측정 참고 : PL 스펙트럼 및 시간 상관 단일 광자 계수는 실온에서 (TCSPC) 측정가 티 증폭 사용하여 수행 하였다 : 400 nm 파장을 중심으로 50 FSEC 펄스의 기차를 생산하고, 두 번째 고조파 세대 (SHG) 후 사파이어 발진기 및 1.76의 출력 14 mW의. <ol><li> 레이저까지와 검출기에 표본면을 배치 샘플 홀더에 샘플을 수정합니다. 샘플에 초점을 레이저를 맞 춥니 다. 섬유 분광계를 사용하여 900 nm의 파장으로 500 nm 내지 샘플의 PL 방출 스펙트럼을 측정한다. </li><li> (AVA 단일 광자 검출기를 사용하여lanche 포토 다이오드 또는 광전관)은 컬러 유리 필터 및 500 또는 650 nm의 간섭 대역 통과 필터와 시분 PL 수명을 측정 하였다. </li><li> 삽입 된 ZnO, CdSSe, 또는 ZnO의 / CdSSe 샘플 홀더에 슬라이드. 500 nm의 대역 통과 필터와 650 나노 미터 대역 통과 필터와 CdSSe 또는 ZnO의 / CdSSe 샘플 순수의 ZnO 나노 와이어를 측정한다. </li><li> 시간 해결 형광 붕괴 수명을 측정하는 시간 상관 단일 광자 계수기 또는 빠른 오실로스코프를 사용합니다. </li></ol>

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이 문서의 데이터 및 수치는 리 등. (17)에 의해 나노 기술 문헌에서 인용된다.

된 ZnO 나노 와이어 (줄기)의 수직 정렬은 기판 상에 에피 택셜 성장에 기초한다. 된 ZnO 나노 와이어는 사파이어 (12)의 A면의주기와 일치하는 &lt;0001&gt; 방향을 따라 우선적으로 성장한다. 따라서, 유형 및 기판의 품질이 매우 중요하다. 5 nm 내지 20의 기재에 금 코팅의 두께가 다른, 테스트와의 ZnO 나노 와이어의 성장에 유의 한 차이를 보이지 않았다되었다. 산화 아연 나노 와이어의 길이는 ?...

ZnO를 3.3 EV의 밴드 갭 (BG), 고 전자 이동도 및 큰 여기자 바인딩 에너지 1,2 갖춘 II-VI 반도체이다. 그것은 광학 장치의 현재와 미래의 응용 프로그램, 태양 전지, 광촉매의 과다와 풍부한 반도체 물질이다. 그러나, ZnO의 가시 스펙트럼 범위에서의 적용을 제한하는 투명합니다. 따라서, 좁은 갭 반도체 (3), 염료 분자 (4) 및 감광성 중합체 5와 같은 가시 광선을 흡수하는 재료는, 자주 가시광 흡수의 ZnO 민감 위해 사용되어왔다. CD에 (BG 2.43 EV)과의 CdSe (BG 1.76 eV의)는 일반적인 II-VI 좁은 갭 반도체이고 집중적으로 조사되었다. 삼원 합금 CdSSe의 BG 및 격자 매개 변수는 VI 성분 -6,7-의 몰비를 변화시킴으로써 조절 될 수있다. ZnO의 / CdSSe 나노 복합 재료는 효율적인 photov 결과보고되었다oltaic 에너지 변환 8,9. CdSSe 분기 향상된 가시광 흡수성을 갖는 기판으로 수직 배향 된 ZnO 나노 와이어의 효율적인 전자 이동 경로를 결합하여 줄기와 가지 9,10 사이의 효율적인 전자 전달되었다. 따라서, 우리는 수직으로 정렬 된 ZnO 나노 와이어가 CdSSe 가지로 장식되어 새로운 트리 형의 ZnO / CdSSe의 나노 구조를 합성. 이 복합 재료는 신규 태양 에너지 변환 장치를위한 빌딩 블록으로서 작용할 수있다. 이 프로토콜의 ZnO 나노 와이어 어레이는 이전 11 출판 된 절차에 따라, ZnO의 분체 및 C로부터 한 단계 화학 기상 증착 (CVD)에 의해 사파이어 기판 상에 성장하는 방법을 설명한다. 된 ZnO 나노 와이어의 성장에 따라, CVD의 제 2 단계의 산화 아연 나노 와이어 CdSSe 분기 성장이 사용된다. 우리는 X 선 분말 회절 (XRD), 주사 전자 현미경 (SEM) 등을 사용에너지 분산 형 X 선 분광법 (EDS)은 산화 아연 / CdSSe의 nanotrees (NTS)의 결정 구조, 형태, 및 조성물을 측정한다. 분기와 스템 사이의 광학 특성 및 전하 캐리어 운송기구는 광 발광 (PL) 스펙트럼 및 시간 - 분해 PL 수명 측정에 의해 연구되었다.

<table><tbody><tr><td>ZnO</td><td>Sigma Aldrich</td><td>1314-13-2</td><td></td></tr><tr><td>Activated Carbon</td><td>Alfa</td><td>231-153-3</td><td></td></tr><tr><td>CdSe</td><td>Sigma Aldrich</td><td>1306-24-7</td><td></td></tr><tr><td>CdS</td><td>Sigma Aldrich</td><td>1306-23-6</td><td></td></tr><tr><td>Sapphire</td><td>MTI</td><td>2SP</td><td>a-plane, 10 &amp;times; 10 &amp;times; 1 mm</td></tr><tr><td>Furnace</td><td>Lindberg Blue M</td><td>SSP</td><td></td></tr><tr><td>Scanning electron microscope</td><td>Hitachi</td><td>S5700</td><td>assembled with an Oxford Inca X-act detector</td></tr><tr><td>X-ray powder diffractometer</td><td>Rigaku</td><td>MiniFlex</td><td>filtered Cu K&amp;alpha; radiation (&amp;lambda;=1.5418&amp;nbsp;&amp;Aring;)</td></tr><tr><td>Amplified Ti:sapphire oscillator</td><td>Coherent Mantis</td><td>Coherent Legend-Elite</td><td></td></tr><tr><td>Single photon detection module</td><td>ID Quantique</td><td>ID-100</td><td></td></tr><tr><td>Sputter coater</td><td>Cressington</td><td>308</td><td>assembled with gold target</td></tr><tr><td>Fiber probe spectrometer</td><td>Photon Control</td><td>SPM-002</td><td></td></tr><tr><td>Colored Glass Filter</td><td>Thorlabs</td><td>FGB37-A - &amp;Oslash;25 mm BG40</td><td>AR Coated: 350 - 700&amp;nbsp;nm</td></tr><tr><td>Compressed argon gas</td><td>Keen</td><td>7440-37-1</td><td></td></tr></tbody></table>

synthesis of hierarchical zno/cdsse heterostructure nanotrees

두 단계의 화학 기상 증착 방법이 여기에 트리 형 계층의 ZnO / CdSSe 헤테로 - 나노 구조물을 제조하는데 사용된다. 수직 구조는 투명한 사파이어 기판 상에 정렬 된 ZnO 나노 와이어 성장 CdSSe 가지로 구성된다. 형태는 주사 전자 현미경을 통해 측정 하였다. 결정 구조는 X 선 분말 회절 분석에 의해 측정 하였다. ZnO의 양이 줄기 CdSSe 분기 주로 우르 자이 트 결정 구조를 갖는다. CdSSe 지점에서 S 및 Se 몰비는 에너지 분산 X 선 분광법에 의해 측정 하였다. CdSSe 분기 강한 가시광 흡수를 초래한다. 광 발광 (PL) 스펙트럼은 줄기와 가지 유형-II의 이종 접합을 형성하는 것으로 나타났다. 개개의 ZnO로부터 방출 CdSSe 줄기 또는 가지로 비교 CdSSe 및 ZnO의 사이에 고속의 전하 전송을 나타내는 경우 PL 수명 측정은 나무에서 발광 수명의 감소를 보였다. VERTI으 배향 된 ZnO 기판에 직접 전자 전달 경로를 제공하고, 가시광에 의한 광 여기 후 효과적인 전하 분리를 허용 유래한다. 상술 한 특성의 조합 된 ZnO / CdSSe 태양 전지, 광촉매 및 광전자 소자에 응용 프로그램에 대한 유망한 후보를 nanotrees 수 있습니다.

도 1의 ZnO / CdSSe NTS의 성장 메커니즘을 나타낸다. 절차는 비 촉매 증기 - 고체 (VS)의 성장에 이어 촉매 증기 - 액체 - 고체 (VLS) 공정을 포함했다. 제 VLS 공정에서의 ZnO 및 C 금속성 아연과 탄소 산화물의 결과로, 아르곤 분위기 하에서 반응한다. 아연이어서, 사파이어 기판 상에 금 전구체에 용해시킨다. 의 ZnO 나노 와이어는 용해 아연 및 잔류 산소에서 성장. 두 ?...

Watch this Scientific Journal Video about Synthesis of Hierarchical ZnO/CdSSe Heterostructure Nanotrees at JoVE.com

Synthesis of Hierarchical ZnO/CdSSe Heterostructure Nanotrees

여기, 우리는 CdSSe 가지가 수직으로 정렬 된 ZnO 나노 와이어의 성장 소설 나무와 같은 계층의 ZnO / CdSSe 나노 구조를 준비하고 특징. 얻어진 nanotrees 태양 에너지 변환 및 다른 광전자 기기에 대한 잠재적 인 재료이다.

계층의 ZnO / CdSSe 헤테로 Nanotrees의 합성

A two-step chemical vapor deposition procedure is here employed to prepare tree-like hierarchical ZnO/CdSSe hetero-nanostructures. The structures are ...

synthesis-of-hierarchical-znocdsse-heterostructure-nanotrees

Universidad de Cartagena UDEC

Research

JoVE Journal

Chemistry

9.9K 조회수.  University of Delaware.  여기, 우리는 CdSSe 가지가 수직으로 정렬 된 ZnO 나노 와이어의 성장 소설 나무와 같은 계층의 ZnO / CdSSe 나노 구조를 준비하고 특징. 얻어진 nanotrees 태양 에너지 변환 및 다른 광전자 기기에 대한 잠재적 인 재료이다. 

비디오: Synthesis of Hierarchical ZnO/CdSSe Heterostructure Nanotrees

Harvesting Solar Energy by Means of Charge-Separating Nanocrystals and Their Solids

Conjoining different semiconductor materials in a single nano-composite provides synthetic means for the development of novel optoelectronic materials offering a superior control over the spatial distribution of charge carriers across material interfaces. As this study demonstrates, a combination of donor-acceptor nanocrystal (NC) domains in a single nanoparticle can lead to the realization of efficient photocatalytic1-5 materials, while a layered assembly of donor- and acceptor-like nanocrystals films gives rise to photovoltaic materials.
Initially the paper focuses on the synthesis of composite inorganic nanocrystals, comprising linearly stacked ZnSe, CdS, and Pt domains, which jointly promote photoinduced charge separation. These structures are used in aqueous solutions for the photocatalysis of water under solar radiation, resulting in the production of H2 gas. To enhance the photoinduced separation of charges, a nanorod morphology with a linear gradient originating from an intrinsic electric field is used5. The inter-domain energetics are then optimized to drive photogenerated electrons toward the Pt catalytic site while expelling the holes to the surface of ZnSe domains for sacrificial regeneration (via methanol). Here we show that the only efficient way to produce hydrogen is to use electron-donating ligands to passivate the surface states by tuning the energy level alignment at the semiconductor-ligand interface. Stable and efficient reduction of water is allowed by these ligands due to the fact that they fill vacancies in the valence band of the semiconductor domain, preventing energetic holes from degrading it. Specifically, we show that the energy of the hole is transferred to the ligand moiety, leaving the semiconductor domain functional. This enables us to return the entire nanocrystal-ligand system to a functional state, when the ligands are degraded, by simply adding fresh ligands to the system4.
To promote a photovoltaic charge separation, we use a composite two-layer solid of PbS and TiO2 films. In this configuration, photoinduced electrons are injected into TiO2 and are subsequently picked up by an FTO electrode, while holes are channeled to a Au electrode via PbS layer6. To develop the latter we introduce a Semiconductor Matrix Encapsulated Nanocrystal Arrays (SMENA) strategy, which allows bonding PbS NCs into the surrounding matrix of CdS semiconductor. As a result, fabricated solids exhibit excellent thermal stability, attributed to the heteroepitaxial structure of nanocrystal-matrix interfaces, and show compelling light-harvesting performance in prototype solar cells7.

A general strategy for the development of charge-separating semiconductor nanocrystal composites deployable for solar energy production is presented. We show that assembly of donor-acceptor nanocrystal domains in a single nanoparticle geometry gives rise to a photocatalytic function, while bulk-heterojunctions of donor-acceptor nanocrystal films can be used for photovoltaic energy conversion.

충전 분리 Nanocrystals와 고체를 통해 태양 에너지를 수확

Conjoining different semiconductor materials in a single nano-composite provides synthetic means for the development of novel optoelectronic materials ...

연구

공학

Seeded Synthesis of CdSe/CdS Rod and Tetrapod Nanocrystals

We demonstrate a method for the synthesis of multicomponent nanostructures consisting of CdS and CdSe with rod and tetrapod morphologies. A seeded synthesis strategy is used in which spherical seeds of CdSe are prepared first using a hot-injection technique. By controlling the crystal structure of the seed to be either wurtzite or zinc-blende, the subsequent hot-injection growth of CdS off of the seed results in either a rod-shaped or tetrapod-shaped nanocrystal, respectively. The phase and morphology of the synthesized nanocrystals are confirmed using X-ray diffraction and transmission electron microscopy, demonstrating that the nanocrystals are phase-pure and have a consistent morphology. The extinction coefficient and quantum yield of the synthesized nanocrystals are calculated using UV-Vis absorption spectroscopy and photoluminescence spectroscopy. The rods and tetrapods exhibit extinction coefficients and quantum yields that are higher than that of the bare seeds. This synthesis demonstrates the precise arrangement of materials that can be achieved at the nanoscale by using a seeded synthetic approach.

A protocol for the seeded synthesis of rod-shaped and tetrapod-shaped multicomponent nanostructures consisting of CdS and CdSe is presented.

We demonstrate a method for the synthesis of multicomponent nanostructures consisting of CdS and CdSe with rod and tetrapod morphologies. A seeded ...

화학

Ultrahigh Density Array of Vertically Aligned Small-molecular Organic Nanowires on Arbitrary Substrates

In recent years &pi;-conjugated organic semiconductors have emerged as the active material in a number of diverse applications including large-area, low-cost displays, photovoltaics, printable and flexible electronics and organic spin valves. Organics allow (a) low-cost, low-temperature processing and (b) molecular-level design of electronic, optical and spin transport characteristics. Such features are not readily available for mainstream inorganic semiconductors, which have enabled organics to carve a niche in the silicon-dominated electronics market. The first generation of organic-based devices has focused on thin film geometries, grown by physical vapor deposition or solution processing. However, it has been realized that organic nanostructures can be used to enhance performance of above-mentioned applications and significant effort has been invested in exploring methods for organic nanostructure fabrication.	
A particularly interesting class of organic nanostructures is the one in which vertically oriented organic nanowires, nanorods or nanotubes are organized in a well-regimented, high-density array. Such structures are highly versatile and are ideal morphological architectures for various applications such as chemical sensors, split-dipole nanoantennas, photovoltaic devices with radially heterostructured "core-shell" nanowires, and memory devices with a cross-point geometry. Such architecture is generally realized by a template-directed approach. In the past this method has been used to grow metal and inorganic semiconductor nanowire arrays. More recently &pi;-conjugated polymer nanowires have been grown within nanoporous templates. However, these approaches have had limited success in growing nanowires of technologically important &pi;-conjugated small molecular weight organics, such as tris-8-hydroxyquinoline aluminum (Alq3), rubrene and methanofullerenes, which are commonly used in diverse areas including organic displays, photovoltaics, thin film transistors and spintronics.	
Recently we have been able to address the above-mentioned issue by employing a novel "centrifugation-assisted" approach. This method therefore broadens the spectrum of organic materials that can be patterned in a vertically ordered nanowire array. Due to the technological importance of Alq3, rubrene and methanofullerenes, our method can be used to explore how the nanostructuring of these materials affects the performance of aforementioned organic devices. The purpose of this article is to describe the technical details of the above-mentioned protocol, demonstrate how this process can be extended to grow small-molecular organic nanowires on arbitrary substrates and finally, to discuss the critical steps, limitations, possible modifications, trouble-shooting and future applications.

We report a simple method for fabricating an ultrahigh density array of vertically ordered small-molecular organic nanowires. This method allows for synthesis of complex heterostructured hybrid nanowire geometries, which can be inexpensively grown on arbitrary substrates. These structures have potential applications in organic electronics, optoelectronics, chemical sensing, photovoltaics and spintronics.

임의 기판에 수직으로 정렬 작은 분자 유기 나노 와이어의 초 밀도 배열

In  recent years &pi;-conjugated  organic semiconductors have emerged as the active material in a number of  diverse applications including large-area, ...

Atomically Defined Templates for Epitaxial Growth of Complex Oxide Thin Films

Atomically defined substrate surfaces are prerequisite for the epitaxial growth of complex oxide thin films. In this protocol, two approaches to obtain such surfaces are described. The first approach is the preparation of single terminated perovskite SrTiO3 (001) and DyScO3 (110) substrates. Wet etching was used to selectively remove one of the two possible surface terminations, while an annealing step was used to increase the smoothness of the surface. The resulting single terminated surfaces allow for the heteroepitaxial growth of perovskite oxide thin films with high crystalline quality and well-defined interfaces between substrate and film. In the second approach, seed layers for epitaxial film growth on arbitrary substrates were created by Langmuir-Blodgett (LB) deposition of nanosheets. As model system Ca2Nb3O10- nanosheets were used, prepared by delamination of their layered parent compound HCa2Nb3O10. A key advantage of creating seed layers with nanosheets is that relatively expensive and size-limited single crystalline substrates can be replaced by virtually any substrate material.

Various procedures are outlined to prepare atomically defined templates for epitaxial growth of complex oxide thin films. Chemical treatments of single crystalline SrTiO3 (001) and DyScO3 (110) substrates were performed to obtain atomically smooth, single terminated surfaces. Ca2 Nb3 O10- nanosheets were used to create atomically defined templates on arbitrary substrates.

복합 산화물 박막의 에피 택셜 성장을위한 원자 적으로 정의 된 템플릿

Atomically defined substrate surfaces are prerequisite for the epitaxial growth of complex oxide thin films. In this protocol, two approaches to obtain ...

Preparation of ZnO Nanorod/Graphene/ZnO Nanorod Epitaxial Double Heterostructure for Piezoelectrical Nanogenerator by Using Preheating Hydrothermal

Well-aligned ZnO nanostructures have been intensively studied over the last decade for remarkable physical properties and enormous applications. Here, we describe a one-step fabrication technique to synthesis freestanding ZnO nanorod/graphene/ZnO nanorod double heterostructure. The preparation of the double heterostructure is performed by using thermal chemical vapor deposition (CVD) and preheating hydrothermal technique. In addition, the morphological properties were characterized by using the scanning electron microscopy (SEM). The utility of freestanding double heterostructure is demonstrated by fabricating the piezoelectric nanogenerator. The electrical output is improved up to 200% compared to that of a single heterostructure owing to the coupling effect of the piezoelectricity between the arrays of ZnO nanorods on the top and bottom of graphene. This unique double heterostructure have a tremendous potential for applications of electrical and optoelectrical devices where the high number density and specific surface area of nanorod are needed, such as pressure sensor, immuno-biosensor and dye-sensitized solar cells.

One-step fabrication method for obtaining freestanding epitaxial double heterostructure is presented. This approach could achieve ZnO coverage with a higher number density than that of the epitaxial single heterostructure, leading to a piezoelectric nanogenerator with an increased output electrical performance.

예열 열수를 사용하여 Piezoelectrical 나노 발전기에 대한의 ZnO 나노 막대 / 그래 핀 / ZnO의 나노로드 에피 택셜 더블 헤테로 구조의 제조

Well-aligned ZnO nanostructures have been intensively studied over the last decade for remarkable physical properties and enormous applications. Here, we ...

Well-aligned Vertically Oriented ZnO Nanorod Arrays and their Application in Inverted Small Molecule Solar Cells

This manuscript describes how to design and fabricate efficient inverted solar cells, which are based on a two-dimensional conjugated small molecule (SMPV1) and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM), by utilizing ZnO nanorods (NRs) grown on a high quality Al-doped ZnO (AZO) seed layer. The inverted SMPV1:PC71BM solar cells with ZnO NRs that grew on both a sputtered and sol-gel processed AZO seed layer are fabricated. Compared with the AZO thin film prepared by the sol-gel method, the sputtered AZO thin film exhibits better crystallization and lower surface roughness, according to X-ray diffraction (XRD) and atomic force microscope (AFM) measurements. The orientation of the ZnO NRs grown on a sputtered AZO seed layer shows better vertical alignment, which is beneficial for the deposition of the subsequent active layer, forming better surface morphologies. Generally, the surface morphology of the active layer mainly dominates the fill factor (FF) of the devices. Consequently, the well-aligned ZnO NRs can be used to improve the carrier collection of the active layer and to increase the FF of the solar cells. Moreover, as an anti-reflection structure, it can also be utilized to enhance the light harvesting of the absorption layer, with the power conversion efficiency (PCE) of solar cells reaching 6.01%, higher than the sol-gel based solar cells with an efficiency of 4.74%.

This manuscript describes how to design and fabricate efficient inverted SMPV1:PC71BM solar cells with ZnO nanorods (NRs) grown on a high quality Al-doped ZnO (AZO) seed layer. The well-aligned vertically oriented ZnO NRs exhibit high crystalline properties. The power conversion efficiency of solar cells can reach 6.01%.

잘 정렬 된 수직 지향 ZnO Nanorod 배열 및 그들의 응용 프로그램에서 반전 된 작은 분자 태양 전지

This manuscript describes how to design and fabricate efficient inverted solar cells, which are based on a two-dimensional conjugated small molecule ...

A Standard and Reliable Method to Fabricate Two-Dimensional Nanoelectronics

Two-dimensional (2D) materials have attracted huge attention due to their unique properties and potential applications. Since wafer scale synthesis of 2D materials is still in nascent stages, scientists cannot fully rely on traditional semiconductor techniques for related research. Delicate processes from locating the materials to electrode definition need to be well controlled. In this article, a universal fabrication protocol required in manufacturing nanoscale electronics, such as 2D quasi-heterojunction bipolar transistors (Q-HBT), and 2D back-gated transistors are demonstrated. This protocol includes the determination of material position, electron beam lithography (EBL), metal electrode definition, et al. A step by step narrative of the fabrication procedures for these devices are also presented. Furthermore, results show that each of the fabricated devices has achieved high performance with high repeatability. This work reveals a comprehensive description of process flow for preparing 2D nano-electronics, enables the research groups to access this information, and pave the way toward future electronics.

The article aims to introduce a standard and reliable fabrication procedure for the development of future low dimensional nanoelectronics.

2 차원 일렉트로닉스를 조작 하는 표준 및 신뢰할 수 있는 방법

Two-dimensional (2D) materials have attracted huge attention due to their unique properties and potential applications. Since wafer scale synthesis of 2D ...

Fabrication of Schottky Diodes on Zn-polar BeMgZnO/ZnO Heterostructure Grown by Plasma-assisted Molecular Beam Epitaxy

Heterostructure field effect transistors (HFETs) utilizing a two dimensional electron gas (2DEG) channel have a great potential for high speed device applications. Zinc oxide (ZnO), a semiconductor with a wide bandgap (3.4 eV) and high electron saturation velocity has gained a great deal of attention as an attractive material for high speed devices. Efficient gate modulation, however, requires high-quality Schottky contacts on the barrier layer. In this article, we present our Schottky diode fabrication procedure on Zn-polar BeMgZnO/ZnO heterostructure with high density 2DEG which is achieved through strain modulation and incorporation of a few percent Be into the MgZnO-based barrier during growth by molecular beam epitaxy (MBE). To achieve high crystalline quality, nearly lattice-matched high-resistivity GaN templates grown by metal-organic chemical vapor deposition (MOCVD) are used as the substrate for the subsequent MBE growth of the oxide layers. To obtain the requisite Zn-polarity, careful surface treatment of GaN templates and control over the VI/II ratio during the growth of low temperature ZnO nucleation layer are utilized. Ti/Au electrodes serve as Ohmic contacts, and Ag electrodes deposited on the O2 plasma pretreated BeMgZnO surface are used for Schottky contacts.

Attainment of high-quality Schottky contacts is imperative for achieving efficient gate modulation in heterostructure field effect transistors (HFETs). We present the fabrication methodology and characteristics of Schottky diodes on Zn-polar BeMgZnO/ZnO heterostructures with high-density two dimensional electron gas (2DEG), grown by plasma-assisted molecular beam epitaxy on GaN templates.

Heterostructure field effect transistors (HFETs) utilizing a two dimensional electron gas (2DEG) channel have a great potential for high speed device ...

Growth of Gold Dendritic Nanoforests on Titanium Nitride-coated Silicon Substrates

In this study, a high-power impulse magnetron sputtering system is used to coat a flat and firm titanium nitride (TiN) film on silicon (Si) wafers, and a fluoride-assisted galvanic replacement reaction (FAGRR) is employed for the rapid and easy deposition of gold dendritic nanoforests (Au DNFs) on the TiN/Si substrates. Scanning electron microscopy (SEM) images and energy-dispersive X-ray spectroscopy patterns of TiN/Si and Au DNFs/TiN/Si samples validate that the synthesis process is accurately controlled. Under the reaction conditions in this study, the thickness of the Au DNFs increases linearly to 5.10 &#177; 0.20 &#181;m within 15 min of the reaction. Therefore, the employed synthesis procedure is a simple and rapid approach for preparing Au DNFs/TiN/Si composites.

This study presents a feasible procedure for synthesizing gold dendritic nanoforests on titanium nitride/silicon substrates. The thickness of gold dendritic nanoforests increases linearly within 15 min of a synthesis reaction.

질 화 티타늄 코팅 된 실리콘 기질에 대 한 금 수지상 나노 숲의 성장

In this study, a high-power impulse magnetron sputtering system is used to coat a flat and firm titanium nitride (TiN) film on silicon (Si) wafers, and a ...

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations

Computational tools based on density-functional theory (DFT) enable the exploration of the qualitatively new, experimentally attainable nanoscale compounds for a targeted application. Theoretical simulations provide a profound understanding of the intrinsic electronic properties of functional materials. The goal of this protocol is to search for photocatalyst candidates by computational dissection. Photocatalytic applications require suitable band gaps, appropriate band edge positions relative to the redox potentials. Hybrid functionals can provide accurate values of these properties but are computationally expensive, whereas the results at the Perdew-Burke-Ernzerhof (PBE) functional level could be effective for suggesting strategies for band structure engineering via electric field and tensile strain aiming to enhance the photocatalytic performance. To illustrate this, in the present manuscript, the DFT based simulation tool VASP is used to investigate the band alignment of nanocomposites in combinations of nanotubes and nanoribbons in the ground state. To address the lifetime of photogenerated holes and electrons in the excited state, nonadiabatic dynamics calculations are needed.

Calculations performed by the Vienna Ab initio Simulation Package can be used to identify the intrinsic electronic properties of nanoscale materials and predict the potential water-splitting photocatalysts.