Optoelectronic characterization of morphology-controlled zinc oxide nanowires

2011 ◽  
Vol 1315 ◽  
Author(s):  
Shou-Yi Kuo ◽  
Fang-I Lai ◽  
Chun-Chieh Wang ◽  
Woei-Tyng Lin
Keyword(s):  
Field Emission ◽  
Visible Region ◽  
Chemical Vapor ◽  
Growth Time ◽  
Emission Measurement ◽  
Oxide Nanowires ◽  
Average Reflectance ◽  
Vertically Aligned ◽  
Metal Catalyzed

ABSTRACTIn this paper, we report the characterization of vertically aligned ZnO nanowire (NW) arrays synthesized by metal-catalyzed chemical vapor deposition. The growth mechanism of ZnO NWs may be related to vapor-solid-nucleation. Morphological, structural, optical and field emission characteristics can be modified by varying the growth time. For growth time reaches 120 min, the length and the diameter of ZnO NWs are 1.5 μm and 350 nm, and they also show preferential growth orientation along the c-axis. Moreover, strong alignment and uniform distribution of ZnO NWs can effectively enhance the antireflection to reach the average reflectance of 5.7% in the visible region as well. Field emission measurement indicated that the growth time play an important role in density- and morphology-controlled ZnO NWs, and thus ZnO NWs are expected to be used in versatile optoelectronic devices.

Characterization of High Quality, Large-Scale Growth of Monolayer WS2 Domains via Chemical Vapor Deposition Technique

2021 ◽  
Author(s):  
Somayeh Asgary ◽  
Amir Hoshang Ramezani ◽  
Zhaleh Ebrahimi Nejad
Keyword(s):  
Large Scale ◽  
Average Length ◽  
Chemical Vapor ◽  
Growth Time ◽  
High Quality ◽  
Force Microscopy ◽  
Atomic Force ◽  
Regular Triangle ◽  
Vapor Deposition Technique

Abstract WS2 flakes have been grown successfully on SiO2 substrate via chemical vapor (CVD) deposition method by reduction and sulfurization of WO3 using Ar/ H2 gas and sulfur evaporated from solid sulfur powder. The prepared samples were characterized by optical microscopy (OM), atomic force microscopy (AFM), scanning electron microscopy (SEM), Raman spectra and photoluminescence (PL). Large domain WS2 monolayers are obtained by extending the growth time. The perfect triangular single-crystalline WS2 flakes with an average length of more than 35 µm were achieved. The sharp PL peak (∼1.98 eV) and two distinct Raman peaks (E2g and A1g) with a ∼ 71.5 cm-1 peak split indicating that relatively high quality WS2 crystals with a regular triangle shape can be synthesized. Higher growth time shows larger triangular-shaped of WS2.

The Effect of Ion Implantation on Field Emission Property of Nanodiamond Films

2008 ◽  
Vol 8 (8) ◽  
pp. 4141-4145 ◽  
Author(s):  
Huang-Chin Chen ◽  
Umesh Palnitkar ◽  
Huan Niu ◽  
Hsiu-Fung Cheng ◽  
I-Nan Lin
Keyword(s):  
Ion Implantation ◽  
Field Emission ◽  
Structural Damage ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Nanocrystalline Diamond ◽  
Emission Measurement ◽  
Before And After ◽  
Nitrogen Ions ◽  
Nitrogen Ion

Nanocrystalline diamond films prepared by microwave plasma enhanced chemical vapor deposition (MPECVD) were implanted using 110 keV nitrogen ions under fluence ranging from 1013–1014 ions/cm2. Scanning Electron Microscopy (SEM) and Raman spectroscopy were used to analyze the changes in the surface of the films before and after ion implantation. Results show that with nitrogen ion implantation in nanocrystalline diamond film cause to decrease in diamond crystallinity. The field emission measurement shows a sharp increase in current density with increase in dose. The ion implantation also alters the turn on field. It is observed that the structural damage caused by ion implantation plays a significant role in emission behaviour of nanocrystalline diamonds.

Field Emission of Aluminum Nitride Nanocones Deposited on Titanium Substrate

2010 ◽  
Vol 129-131 ◽  
pp. 476-481 ◽  
Author(s):  
Ye Min Hu ◽  
Zheng Hu ◽  
Fan Zhang ◽  
Ying Li ◽  
Ming Yuan Zhu ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Aluminum Nitride ◽  
Silicon Wafer ◽  
Field Emission ◽  
Electron Emission ◽  
Vapor Deposition ◽  
Titanium Substrate ◽  
Chemical Vapor ◽  
Emission Measurement ◽  
Turn On

We report the preparation of quasi-arrays of aluminum nitride nanocones via chemical vapor deposition on nitriding treated titanium substrate at 800 °C through the reaction between AlCl3 vapor and NH3/N2 gas. The field emission measurement exhibits a fine electron emission with the turn-on field of 10.7 V/mm, which is quite smaller than the turn-on field of 41.3 V/μm for aluminum nitride nanocones deposited on silicon wafer in our previous works. The reduction of turn-on field is attributed to the formation of a layer of conductive tiannium nitride on titanium substrate during the nitriding treatment.

Vertical Aligned CNT Growth on Metals for Direct Use With Electrical Conductance

2010 ◽  
Vol 1258 ◽  
Author(s):  
Jin-Ju Kim ◽  
Byeong-Joo Lee ◽  
Goo-Hwan Jeong
Keyword(s):  
Vapor Deposition ◽  
Electrical Conductance ◽  
Lithium Ion ◽  
Chemical Vapor ◽  
Tube Length ◽  
Growth Time ◽  
Inconel 600 ◽  
Thermal Chemical Vapor Deposition ◽  
Vertically Aligned ◽  
Direct Use

AbstractWe present growth of vertically aligned carbon nanotube (VCNT) on metal substrates such as Cu foils, Inconel 600 and stainless steel (SUS316L) using thermal chemical vapor deposition (TCVD) in order to get a low contact resistance at interface between CNT and substrates for future applications. The temperature range for VCNT growth was 700-775 °C and mixtures of acetylene, argon and hydrogen were used as processing gas. The tube length was controlled by growth time and temperature. Finally, we successfully grew the VCNT on Cu foils over 1 cm2 and confirmed the excellent electrical conductance which can be directly used as anodic electrode in lithium ion battery. On the other hand, the growth of VCNT on Inconel 600 or SUS316L sheets was carried out as purchased. These tubes are expected to be useful for field emission devices.

Controlled Growth and Supercapacitive Behaviors of CVD Carbon Nanotube Arrays

2011 ◽  
Vol 688 ◽  
pp. 11-18 ◽  
Author(s):  
Dan Dan Zhao ◽  
Zhi Yang ◽  
Hao Wei ◽  
Ya Fei Zhang
Keyword(s):  
Carbon Nanotube ◽  
Particle Density ◽  
Chemical Vapor ◽  
Growth Time ◽  
Controlled Growth ◽  
Si Substrate ◽  
Graphene Layers ◽  
Wide Range ◽  
Cnt Arrays ◽  
Vertically Aligned

Low-pressure chemical vapor deposition (LP-CVD) technique has been utilized for controlled growth of carbon nanotube (CNT) arrays on silicon wafers. The tube-diameters of CNTs and the number of graphene layers are controlled by varying the thickness of catalyst films. The catalyst particle density and the growth conditions such as the ambient gas and the local environment are all crucial for the formation of vertically aligned CNT arrays. The length of CNT arrays can be controlled by altering the growth time. In addition, the supercapacitive properties of CNT arrays with various morphologies growing on different current collectors have been investigated using a less corrosive 0.5 M Na2SO4aqueous solution as the electrolyte. Vertically aligned CNT arrays on Ti-Si substrate produce a higher capacitance compared to randomly oriented CNTs on the same current collector. Furthermore, Ni foam enables better utilization of active materials than Ti-Si substrate. CNT arrays electrodes fabricated by this simple, low cost approach demonstrate stable and consistent capacitor behaviors for a wide range of scan rates. Moreover, CNT arrays electrodes provide better platform for further integration with transitional metal oxide, via simple sputtering or electrodeposition technique, to enhance the supercapacitive performance.

scholarly journals Structure and Characterization of Vertically Aligned Single-Walled Carbon Nanotube Bundles

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Francisco Márquez ◽  
Vicente López ◽  
Carmen Morant ◽  
Rolando Roque-Malherbe ◽  
Concepción Domingo ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Small Groups ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Nanotube Bundles ◽  
Constant Diameter ◽  
Vertically Aligned

Arrays of vertically aligned single-walled carbon nanotube bundles, SWCNTs, have been synthesized by simple alcohol catalytic chemical vapor deposition process, carried out at 800∘C. The formed SWCNTs are organized in small groups perpendicularly aligned and attached to the substrate. These small bundles show a constant diameter ofca.30 nm and are formed by the adhesion of no more than twenty individual SWCNTs perfectly aligned along their length.

Process Design for the Flow of Ethanol Chemical Vapor Deposition Grown Vertically Aligned Single Walled Carbon Nanotubes

2012 ◽  
Author(s):  
Hatem Abuhimd ◽  
Abe Zeid ◽  
Yung Joon Jung ◽  
Sagar Kamarthi
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Single Walled Carbon Nanotubes ◽  
Growth Time ◽  
Single Walled Carbon ◽  
Vertically Aligned ◽  
Walled Carbon Nanotubes

Carbon nanotubes (CNTs) have received much attention from both the scientific and industrial communities due to their structural properties and unique morphology. There has also been growing interest in vertically aligned single walled carbon nanotubes (VA-SWNTs) because of their suitability for building devices such as solar cells and nanomembrane. Various methods including chemical vapor deposition (CVD) have been developed for growing VA-SWNTs. Among them is alcohol catalytic CVD which is well known for its economic viability, comprehensive substrates selectivity and good yield of VA-SWNTs. This work studies the length assurance of VA-SWNTs growth by an experimental design and an artificial neural network (ANN) metamodel. Process analysis shows that the interaction between gas flow rate and growth time are the most significant input factors. In addition, with high probability flow rate less than 150 sccm and a growth time of 20 minutes are suitable for the repeatability of medium length VA-SWNTs.

scholarly journals Fabrication and Characterization of Inverted Silicon Pyramidal Arrays with Randomly Distributed Nanoholes

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 931
Author(s):  
Yue Zhao ◽  
Kaiping Zhang ◽  
Hailiang Li ◽  
Changqing Xie
Keyword(s):  
Contact Angle ◽  
Chemical Etching ◽  
Visible Region ◽  
Wet Etching ◽  
Electromagnetic Simulation ◽  
Practical Applications ◽  
Average Reflectance ◽  
Metal Assisted Chemical Etching ◽  
Fabrication And Characterization

We report the fabrication, electromagnetic simulation and measurement of inverted silicon pyramidal arrays with randomly distributed nanoholes that act as an anti-reflectivity coating. The fabrication route combines the advantages of anisotropic wet etching and metal-assisted chemical etching. The former is employed to form inverted silicon pyramid arrays, while the latter is used to generate randomly distributed nanoholes on the surface and sidewalls of the generated inverted silicon pyramidal arrays. We demonstrate, numerically and experimentally, that such a structure facilitates the multiple reflection and absorption of photons. The resulting nanostructure can achieve the lowest reflectance of 0.45% at 700 nm and the highest reflectance of 5.86% at 2402 nm. The average reflectance in the UV region (250–400 nm), visible region (400–760 nm) and NIR region (760–2600 nm) are 1.11, 0.63 and 3.76%, respectively. The reflectance at broadband wavelength (250–2600 nm) is 14.4 and 3.4 times lower than silicon wafer and silicon pyramids. In particular, such a structure exhibits high hydrophobicity with a contact angle up to 132.4°. Our method is compatible with well-established silicon planar processes and is promising for practical applications of anti-reflectivity coating.

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