这项研究得到了无人驾驶车辆先进的核心技术研究和开发方案的支持, 这是由科学、信通技术和未来规划部资助的无人驾驶车辆高级研究中心 (UVARC), 大韩民国 (2016M1B3A1A01937575)

警告: 在本协议中使用的某些化学品 (如 、缓冲氧化物蚀刻、异丙醇、 等) 可能对健康有害。在进行任何样品准备之前, 请查阅所有相关的材料安全数据表。在处理蚀刻和溶剂时, 使用适当的个人防护设备 ( 例如 、实验室大衣、安全眼镜、手套、 等 ) 和工程控制 (如 、湿站、油烟罩等). 
 1. 制备 Si 衬底 <ol> <li> 使用金刚石刀具, 将4英寸硅片切成 2 cm x 2 厘米大小的正方形。为了制作彩色样品, 基板通常是切割 2 cm x 2 厘米, 但可以更大, 取决于样品持有人用于倾斜角沉积的大小. </li>
	<li> 要使用聚四氟乙烯 (PTFE) 铲取本机氧化物, 请在缓冲氧化物蚀刻 (BOE) 中浸出切割硅衬底 3. 警告 : 请穿戴适当的安全防护。
	<li> 在丙酮、异丙醇 (国际音标) 和去离子 (DI) 水中依次清除 3 s 中的裂解 Si 衬底. 
	<ol> <li> 使用聚四氟乙烯清洗夹具, 在3分钟的频率为35赫的情况下, 用丙酮在超声波浴中几种切割 Si 衬底. </li>
		<li> 除去丙酮, 用国际音标冲洗所切割的 Si 衬底. </li>
		<li> 作为清洗的最后一步, 用 DI 水冲洗所切割的 Si 衬底. </li>
	</ol> </li> <li> 要去除湿气, 用氮气吹枪将干净的衬底用钳子夹住. 和 #160; </li> </ol> 2。沉积的 Au 反射器 <ol> <li> 使用镊子和碳带, 将已清洗的 Si 衬底固定在一个扁平试样架上, 并将支架放置在电子束蒸发器的腔内, 与钛和 Au 源相结合. </li>
	<li> 疏散会议厅1小时, 以达到高真空。真空室的基底压力应为 4 x 10 -6 乇. </li>
	<li> 将 Ti 层作为粘附层沉积到 10 nm 的厚度, 5-7% 的电子束功率以手动方式控制, 在 7.5 kV 的直流电压下, 使沉积速率为1和 #197;/sec. 
	注: 同一厚度的 Cr 层, 而不是钛层, 可以沉积为粘合层. </li>
	<li> 将 Au 层作为反射层沉积到 100 nm 的厚度, 13-15% 的电子束功率在 7.5 kV 的直流电压下以手动方式控制, 从而使沉积速率为2和 #197;/sec. 
	注: Au 反射层厚度可大于 100 nm。在这里沉积 100 nm 的厚度, 使反射层尽可能薄, 同时保持 Au 的光学特性. </li>
	<li> 在 Au 层沉积后, 排出腔室并取出样品。他们将需要重新加载与倾斜样品持有人的倾斜角沉积. </li>
</ol> 3。斜角沉积倾斜试样架的研制 注意: 有几种方法可以用于倾斜沉积, 如 z-axis 旋转恰克 16 , 但这需要设备的改造和薄膜只能一次放置在一个角度。为了有效地观察不同沉积角度产生的颜色变化, 我们采用了样品持有者在不同的角度对样品进行倾斜。为精确, 倾斜样品持有人可以使用金属加工设备。然而, 在本文中, 我们介绍了一个简单的方法, 可以很容易地遵循. 
<ol> <li> 准备由易于弯曲的金属 (如铝) 制成的金属板. </li>
	<li> 将金属板切成三 2 cm x 5 厘米的碎片. </li>
	<li> 将金属片固定在一个量角器旁边的地板上, 握住短边并将金属弯曲到所需的沉积角度 ( 即 、30和 #176;、45和 #176; 以及70和 #176;). </li>
	<li> 使用碳带将弯曲的金属件连接到4英寸样品架上. </li>
</ol> 4。Ge 层的斜角沉积 注意: 在本节中, 请参考在倾斜样品持有人身上的样品的 图 1 中的示意图, 以及多孔的 ge 薄膜, 下面的斜角度沉积. 
<ol> <li> 将四 Au 沉积样品与碳带固定在0和 #176 角的倾斜试样架上, 30 和 #176;, 45 和 #176;, 以及70和 #176; 分别. </li>
	<li> 将倾斜试样架上的金沉积样品加载到电子束蒸发器中, 并用 Ge 源进行斜角沉积. </li>
	<li> 疏散会议厅1小时, 以达到高真空。真空室的基底压力应为 4 x 10 -6 乇. </li>
	<li> 将 Ge 层作为着色层存放, 其 6-8% 的电子束功率在 7.5 kV 的直流电压下以手动方式控制, 从而使沉积速率为1和 #197;/sec。Ge 层在四样品上的沉积厚度分别为 10 nm、15 nm、20 nm 和 25 nm. 
	注: 选择 10 nm、15 nm、20 nm 和 25 nm 的沉积厚度, 便于比较每个沉积角度的颜色变化。可以选择不同的角度和厚度 (5-60 nm) 来实现特定的颜色. </li>
	<li> 在 Ge 层沉积后, 排出腔室并取出样品. </li>
</ol> 5。大面积斜角沉积过程 注意: 如果用于斜角沉积的试样的尺寸很小, 可以通过步骤4中详细描述的过程来制作。但是, 如果要制作的样品的尺寸很大, 由于 z-axis 16 的蒸发通量的变化, 很难维持胶片的均匀性。因此, 需要一个单独的额外过程, 步骤 5, 是制造更大的样品和达到统一的颜色. 
<ol> <li> 对于2英寸的硅片, 在步骤2中的大样本上沉积 au 层后, 将 au 沉积的大样本固定到45和 #176; 倾斜样本持有者. 
	注: 由于我们的倾斜样品持有人设计为适合小样本, 加载大样本的所有角度 ( 即 , 0 和 #176;, 30 和 #176;, 45 和 #176;, 70 和 #176;) 将在样本之间产生干扰。因此, 在一个过程中, 要在不同的角度倾斜地沉积大型样品, 就必须有一个适合于大型样品的倾斜试样夹. </li>
	<li> 在倾斜试样架上将 Au 沉积的大样本加载到电子束蒸发器中, 并用 Ge 源进行斜角沉积. 
	注: 当加载样品时, 第二沉积层必须与第一沉积物的方向相同, 所以请注意所载样品的方向。为方便起见, 建议将样品夹装在会议厅正面. </li>
	<li> 疏散会议厅1小时至达到高真空。真空室的基底压力应为 4 x 10 -6 乇. </li>
	<li> 将 Ge 层沉积为着色层, 沉积厚度为 10 nm, 这是目标厚度的一半 20 nm, 6-8% 的电子束功率控制在手动模式的直流电压为 7.5 kV, 这给了沉积率1和 #197;/sec. </li>
	<li> 在第一个 Ge 层的沉积完成后, 排出腔室并取出样品, 因为样品需要重新定位和重装. </li>
	<li> 将样品固定在倾斜的样品持有者的位置上, 就第一次沉积的位置而言是颠倒的. </li>
	<li> 将样品装在带有 Ge 源的倾斜样品持有者上, 以便持卡人与第一个沉积物的方向相同. </li>
	<li> 疏散会议厅1小时, 以达到高真空。真空室的基底压力应为 4 x 10 -6 乇. </li>
	<li> 将 Ge 层沉积为着色层, 沉积厚度为 10 nm, 这是目标厚度的一半 20 nm, 6-8% 的电子束功率控制在手动模式的直流电压为 7.5 kV, 这给了沉积率1和 #197;/sec. </li>
	<li> 在 Ge 层沉积后, 排出腔室并取出样品. </li>
</ol>

<ol>
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作者没有什么可透露的。

在常规的着色薄膜涂层中,3、4、5、6, 可以通过改变不同的材质和调整厚度来控制颜色。材料的选择以不同的折射率是有限的调整各种各样的颜色。为了放宽这一限制, 我们利用斜角沉积法对薄膜色层进行了处理。根据沉积角度的不同, Ge 层的孔隙率由原子阴影11改变, 如<strong class="xfig...

一般而言, 薄膜光学涂层的性能是基于它们产生的光干涉的类型, 如高反射或透射。在介质薄膜中, 光干扰可以通过满足条件, 如四分之一波厚度 (λ/4 n) 得到。干涉原理早已被用于各种光学应用, 如法布里-珀罗干涉仪和分布式布拉格反射器1,2。近年来, 使用高吸水性材料如金属和半导体的薄膜结构得到了广泛的研究3,4,5,6。薄膜涂层上的吸收性半导体材料可以获得强光干扰, 在反射波中产生不平凡的相变。这种类型的结构允许超薄涂层比介质薄膜涂层更薄。
最近, 我们研究了利用孔隙率7提高高吸水性薄膜的色调谐和色纯度的方法。通过控制沉积膜的孔隙率, 可以改变薄膜介质的有效折射率8。这种有效折射率的变化使得光学特性得以改善。在此基础上, 利用严格耦合波分析 (RCWA)9, 设计了不同厚度和孔隙的超薄型彩色薄膜。我们的设计在每个孔隙度7中呈现不同胶片厚度的颜色。
采用了一种简单的斜角沉积方法来控制高吸水性薄膜涂层的孔隙率。斜角沉积技术基本上结合了一个典型的沉积系统, 如电子束蒸发器或热蒸发器, 与倾斜的基板10。入射通量的倾斜角产生原子阴影, 从而产生蒸汽通量无法直接到达11的区域。斜角沉积技术在各种薄膜涂层应用中得到了广泛使用12,13,14。
在这项工作中, 我们详细介绍了利用电子束蒸发器的斜淀积制备超薄彩色薄膜的工艺。另外, 还分别介绍了大面积加工的其他方法。除了工艺步骤外, 还详细说明了在制作过程中应注意的一些问题。
我们还回顾了测量加工样品的反射率并将它们转换成颜色信息进行分析的过程, 这样它们就可以用 CIE 的颜色坐标和 RGB 值15来表示。此外, 还讨论了超薄彩色薄膜制作过程中应考虑的一些问题。

<table border="0" cellpadding="0" cellspacing="0" width="757">
	<tbody>
		<tr height="23">
			<td height="23" style="height:23px;width:216px;">&#160;KVE-2004L</td>
			<td style="width:185px;">Korea Vacuum Tech. Ltd.</td>
			<td style="width:129px;"></td>
			<td style="width:227px;">E-beam evaporator system</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Cary 500</td>
			<td style="width:185px;">Varian, USA</td>
			<td style="width:129px;"></td>
			<td>UV-Vis-NIR spectrophotometer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">T1-H-10</td>
			<td style="width:185px;">Elma</td>
			<td style="width:129px;"></td>
			<td style="width:227px;">Ultrasonic bath</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">HSD150-03P</td>
			<td style="width:185px;">Misung Scientific Co., Ltd</td>
			<td style="width:129px;"></td>
			<td style="width:227px;">Hot plate</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Isopropyl Alcohol (IPA)</td>
			<td style="width:185px;">OCI Company Ltd.</td>
			<td style="width:129px;"></td>
			<td style="width:227px;">Isopropyl Alcohol (IPA)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Buffered Oxide Etch 6:1</td>
			<td style="width:185px;">Avantor</td>
			<td style="width:129px;"></td>
			<td style="width:227px;">Buffered Oxide Etch 6:1</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Acetone</td>
			<td style="width:185px;">OCI Company Ltd.</td>
			<td style="width:129px;"></td>
			<td style="width:227px;">Acetone</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">4inch Silicon Wafer</td>
			<td style="width:185px;">Hi-Solar Co., Ltd.</td>
			<td style="width:129px;"></td>
			<td style="width:227px;">4inch Silicon Wafer (P-100, 1-20 ohm.cm, Single side polished, Thickness: 440&#177;20&#956;m)</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">2inch Silicon Wafer</td>
			<td style="width:185px;">Hi-Solar Co., Ltd.</td>
			<td style="width:129px;"></td>
			<td style="width:227px;">2inch Silicon Wafer (P-100, 1-20 ohm.cm, Single side polished, Thickness: 440&#177;20&#956;m)</td>
		</tr>
	</tbody>
</table>

fabrication of ultra-thin color films with highly absorbing media using oblique angle deposition

超薄薄膜结构已被广泛应用于光学涂层, 但性能和制造方面的挑战依然存在。 提出了一种改进的超薄型彩色薄膜的制备方法。建议的过程涉及几个制造问题, 包括大面积处理。具体地说, 该协议描述了使用电子束蒸发器在硅 (Si) 衬底上的锗 (Ge) 和金 (Au) 的斜角沉积制备超薄彩色胶片的过程。 由斜角沉积产生的薄膜孔隙率导致超薄薄膜的颜色变化。颜色变化程度取决于沉积角度和膜厚等因素。超薄彩色薄膜的制备样品显示出改进的颜色调谐和颜色纯度。此外, 将所测样品的反射率转化为色值, 并根据颜色进行分析。我们的超薄薄膜制作方法可望用于各种超薄薄膜应用, 如柔性色电极、薄膜太阳能电池和光学滤光片等。此外, 在这里开发的过程中分析的颜色, 制作样品是广泛的有用的研究各种颜色结构。

图 2a显示了 2 cm x 2 cm 制作样品的图像。样品被制作了, 以便影片有不同的厚度 (即, 10 毫微米, 15 毫微米, 20 毫微米和25毫微米) 并且被存放了在不同的角度 (即, 0 °, 30 °, 45 °和 70)。沉积薄膜的颜色随样品厚度和沉积角度的不同而变化。颜色的变化是由于薄膜孔隙度的变化引起的。根据沉积角度, 在基板上创建单个纳米柱的倾斜阵列, 如图 2?...

Watch this Scientific Journal Video about Fabrication of Ultra-thin Color Films with Highly Absorbing Media Using Oblique Angle Deposition at JoVE.com

Fabrication of Ultra-thin Color Films with Highly Absorbing Media Using Oblique Angle Deposition

用斜角沉积法制备高吸收介质的超薄彩色薄膜

本文介绍了一种改进的光学涂层超薄型彩色薄膜的制备方法。采用电子束蒸发器的斜角沉积技术可提高色调谐和纯度。利用反射测量和颜色信息转换, 分析了锗和 Au 在 Si 衬底上的制备膜。

Ultra-thin film structures have been studied extensively for use as optical coatings, but performance and fabrication challenges remain.&#160; We present ...

fabrication-ultra-thin-color-films-with-highly-absorbing-media-using

Research

JoVE Journal

Engineering

8.2K 次观看.  Gwangju Institute of Science and Technology. 本文介绍了一种改进的光学涂层超薄型彩色薄膜的制备方法。采用电子束蒸发器的斜角沉积技术可提高色调谐和纯度。利用反射测量和颜色信息转换, 分析了锗和 Au 在 Si 衬底上的制备膜。

视频: Fabrication of Ultra-thin Color Films with Highly Absorbing Media Using Oblique Angle Deposition

Fabrication of Nano-engineered Transparent Conducting Oxides by Pulsed Laser Deposition

Nanosecond Pulsed Laser Deposition (PLD) in the presence of a background gas allows the deposition of metal oxides with tunable morphology, structure, density and stoichiometry by a proper control of the plasma plume expansion dynamics. Such versatility can be exploited to produce nanostructured films from compact and dense to nanoporous characterized by a hierarchical assembly of nano-sized clusters. In particular we describe the detailed methodology to fabricate two types of Al-doped ZnO (AZO) films as transparent electrodes in photovoltaic devices: 1) at low O2 pressure, compact films with electrical conductivity and optical transparency close to the state of the art transparent conducting oxides (TCO) can be deposited at room temperature, to be compatible with thermally sensitive materials such as polymers used in organic photovoltaics (OPVs); 2) highly light scattering hierarchical structures resembling a forest of nano-trees are produced at higher pressures. Such structures show high Haze factor (&gt;80%) and may be exploited to enhance the light trapping capability. The method here described for AZO films can be applied to other metal oxides relevant for technological applications such as TiO2, Al2O3, WO3 and Ag4O4.

We describe the experimental method to deposit nanostructured oxide thin films by nanosecond Pulsed Laser Deposition (PLD) in the presence of a background gas. By using this method Al-doped ZnO (AZO) films, from compact to hierarchically structured as nano-tree forests, can be deposited.

制备纳米设计的脉冲激光沉积透明导电氧化物

Nanosecond Pulsed  Laser Deposition (PLD) in the presence of a background gas allows the deposition  of metal oxides with tunable morphology, structure, ...

科研

工程学

Formation of Thick Dense Yttrium Iron Garnet Films Using Aerosol Deposition

Aerosol deposition (AD) is a thick-film deposition process that can produce layers up to several hundred micrometers thick with densities greater than 95% of the bulk. The primary advantage of AD is that the deposition takes place entirely at ambient temperature; thereby enabling film growth in material systems with disparate melting temperatures. This report describes in detail the processing steps for preparing the powder and for performing AD using the custom-built system. Representative characterization results are presented from scanning electron microscopy, profilometry, and ferromagnetic resonance for films grown in this system. As a representative overview of the capabilities of the system, focus is given to a sample produced following the described protocol and system setup. Results indicate that this system can successfully deposit 11 &#181;m thick yttrium iron garnet films that are &#160;&#62; 90% of the bulk density during a single 5 min deposition run. A discussion of methods to afford better control of the aerosol and particle selection for improved thickness and roughness variations in the film is provided.

This report describes the use of a custom-built system to perform aerosol deposition of thick films of yttrium iron garnet onto sapphire substrates at RT. The deposited films are characterized using scanning electron microscopy, profilometry, and ferromagnetic resonance to give a representative overview of the capabilities of the technique.

浓稠钇铁石榴石薄膜的形成使用气溶胶沉积

Aerosol deposition (AD) is a thick-film deposition process that can produce layers up to several hundred micrometers thick with densities greater than 95% ...

Speciation and Bioavailability Measurements of Environmental Plutonium Using Diffusion in Thin Films

The biological uptake of plutonium (Pu) in aquatic ecosystems is of particular concern since it is an alpha-particle emitter with long half-life which can potentially contribute to the exposure of biota and humans. The diffusive gradients in thin films technique is introduced here for in-situ measurements of Pu bioavailability and speciation. A diffusion cell constructed for laboratory experiments with Pu and the newly developed protocol make it possible to simulate the environmental behavior of Pu in model solutions of various chemical compositions. Adjustment of the oxidation states to Pu(IV) and Pu(V) described in this protocol is essential in order to investigate the complex redox chemistry of plutonium in the environment. The calibration of this technique and the results obtained in the laboratory experiments enable to develop a specific DGT device for in-situ Pu measurements in freshwaters. Accelerator-based mass-spectrometry measurements of Pu accumulated by DGTs in a karst spring allowed determining the bioavailability of Pu in a mineral freshwater environment. Application of this protocol for Pu measurements using DGT devices has a large potential to improve our understanding of the speciation and the biological transfer of Pu in aquatic ecosystems.

The technique of diffusive gradients in thin films (DGT) is proposed for speciation studies of plutonium. This protocol describes diffusion experiments probing the behavior of Pu(IV) and Pu(V) in presence of organic matter. DGTs deployed in a karstic spring allow assessment of the bioavailability of Pu.

环境钚的薄膜弥散形态和生物利用度测量

The biological uptake of plutonium (Pu) in aquatic ecosystems is of particular concern since it is an alpha-particle emitter with long half-life which can ...

Indirect Fabrication of Lattice Metals with Thin Sections Using Centrifugal Casting

One of the typical methods to manufacture 3D lattice metals is the direct-metal additive manufacturing (AM) process such as Selective Laser Melting (SLM) and Electron Beam Melting (EBM). In spite of its potential processing capability, the direct AM method has several disadvantages such as high cost, poor surface finish of final products, limitation in material selection, high thermal stress, and anisotropic properties of parts. We propose a cost-effective method to manufacture 3D lattice metals. The objective of this study is to provide a detailed protocol on fabrication of 3D lattice metals having a complex shape and a thin wall thickness; e.g., octet truss made of Al and Cu alloys having a unit cell length of 5 mm and a cell wall thickness of 0.5 mm. An overall experimental procedure is divided into eight sections: (a) 3D printing of sacrificial patterns (b) melt-out of support materials (c) removal of residue of support materials (d) pattern assembly (e) investment (f) burn-out of sacrificial patterns (g) centrifugal casting (h) post-processing for final products. The suggested indirect AM technique provides the potential to manufacture ultra-lightweight lattice metals; e.g., lattice structures with Al alloys. It appears that the process parameters should be properly controlled depending on materials and lattice geometry, observing the final products of octet truss metals by the indirect AM technique.

An indirect additive manufacturing method combining a 3D printing of polymers with a centrifugal casting is outlined for manufacturing 3D octet truss metals (Al and Cu alloys) having a unit cell length of 5 mm with a wall thickness of 0.5 mm.

与超薄切片格金属制造间接使用离心铸造

One of the typical methods to manufacture 3D lattice metals is the direct-metal additive manufacturing (AM) process such as Selective Laser Melting (SLM) ...

A Fabrication Method for Highly Stretchable Conductors with Silver Nanowires

Stretchable electronics are identified as a key technology for electronic applications in the next generation. One of the challenges in fabrication of stretchable electronic devices is the preparation of stretchable conductors with great mechanical stability. In this study, we developed a simple fabrication method to chemically solder the contact points between silver nanowire (AgNW) networks. AgNW nanomesh was first deposited on a glass slide via spray coating method. A reactive ink composed of silver nanoparticle (AgNPs) precursors was applied over the spray coated AgNW thin films. After heating for 40 min, AgNPs were preferentially generated over the nanowire junctions to solder the AgNW nanomesh, and reinforced the conducting network. The chemically modified AgNW thin film was then transferred to polyurethane (PU) substrates by casting method. The soldered AgNW thin films on PU exhibited no obvious change in electrical conductivity under stretching or rolling process with elongation strains up to 120%.

A simple synthesis method is used to chemically solder silver nanowire thin film to fabricate highly stretchable and conductive metal conductors.

对于高伸缩的导线与银纳米线制作方法

Stretchable electronics are identified as a key technology for electronic applications in the next generation. One of the challenges in fabrication of ...

Electrospray Deposition of Uniform Thickness Ge23Sb7S70 and As40S60 Chalcogenide Glass Films

Solution-based electrospray film deposition, which is compatible with continuous, roll-to-roll processing, is applied to chalcogenide glasses. Two chalcogenide compositions are demonstrated: Ge23Sb7S70 and As40S60, which have both been studied extensively for planar mid-infrared (mid-IR) microphotonic devices. In this approach, uniform thickness films are fabricated through the use of computer numerical controlled (CNC) motion. Chalcogenide glass (ChG) is written over the substrate by a single nozzle along a serpentine path. Films were subjected to a series of heat treatments between 100 &#176;C and 200 &#176;C under vacuum to drive off residual solvent and densify the films. Based on transmission Fourier transform infrared (FTIR) spectroscopy and surface roughness measurements, both compositions were found to be suitable for the fabrication of planar devices operating in the mid-IR region. Residual solvent removal was found to be much quicker for the As40S60 film as compared to Ge23Sb7S70. Based on the advantages of electrospray, direct printing of a gradient refractive index (GRIN) mid-IR transparent coating is envisioned, given the difference in refractive index of the two compositions in this study.

Electrospray Deposition of Uniform Thickness Ge23Sb7S70 and As40S60 Chalcogenide Glass Films

A method of uniform thickness solution-derived chalcogenide glass film deposition is demonstrated using computer numerical controlled motion of a single-nozzle electrospray.

厚度均匀葛电沉积<sub&gt; 23</sub&gt;锑<sub&gt; 7</sub&gt;取值<sub&gt; 70</sub&gt;和As<sub&gt; 40</sub&gt;取值<sub&gt; 60</sub&gt;硫系玻璃薄膜

Solution-based electrospray film deposition, which is compatible with continuous, roll-to-roll processing, is applied to chalcogenide glasses. Two ...

Fabrication of Periodic Gold Nanocup Arrays Using Colloidal Lithography

Within recent years, the field of plasmonics has exploded as researchers have demonstrated exciting applications related to chemical and optical sensing in combination with new nanofabrication techniques. A plasmon is a quantum of charge density oscillation that lends nanoscale metals such as gold and silver unique optical properties. In particular, gold and silver nanoparticles exhibit localized surface plasmon resonances-collective charge density oscillations on the surface of the nanoparticle-in the visible spectrum. Here, we focus on the fabrication of periodic arrays of anisotropic plasmonic nanostructures. These half-shell (or nanocup) structures can exhibit additional unique light-bending and polarization-dependent optical properties that simple isotropic nanostructures cannot. Researchers are interested in the fabrication of periodic arrays of nanocups for a wide variety of applications such as low-cost optical devices, surface-enhanced Raman scattering, and tamper indication. We present a scalable technique based on colloidal lithography in which it is possible to easily fabricate large periodic arrays of nanocups using spin-coating and self-assembled commercially available polymeric nanospheres. Electron microscopy and optical spectroscopy from the visible to near-infrared (near-IR) was performed to confirm successful nanocup fabrication. We conclude with a demonstration of the transfer of nanocups to a flexible, conformal adhesive film.

We demonstrate the fabrication of periodic gold nanocup arrays using colloidal lithographic techniques and discuss the importance of nanoplasmonic films.

用胶体光刻制备周期性金 Nanocup 阵列

Within recent years, the field of plasmonics has exploded as researchers have demonstrated exciting applications related to chemical and optical sensing ...

Preparation of Large-area Vertical 2D Crystal Hetero-structures Through the Sulfurization of Transition Metal Films for Device Fabrication

We have demonstrated that through the sulfurization of transition metal films such as molybdenum (Mo) and tungsten (W), large-area and uniform transition metal dichalcogenides (TMDs) MoS2 and WS2 can be prepared on sapphire substrates. By controlling the metal film thicknesses, good layer number controllability, down to a single layer of TMDs, can be obtained using this growth technique. Based on the results obtained from the Mo film sulfurized under the sulfur deficient condition, there are two mechanisms of (a) planar MoS2 growth and (b) Mo oxide segregation observed during the sulfurization procedure. When the background sulfur is sufficient, planar TMD growth is the dominant growth mechanism, which will result in a uniform MoS2 film after the sulfurization procedure. If the background sulfur is deficient, Mo oxide segregation will be the dominant growth mechanism at the initial stage of the sulfurization procedure. In this case, the sample with Mo oxide clusters covered with few-layer MoS2 will be obtained. After sequential Mo deposition/sulfurization and W deposition/sulfurization procedures, vertical WS2/MoS2 hetero-structures are established using this growth technique. Raman peaks corresponding to WS2 and MoS2, respectively, and the identical layer number of the hetero-structure with the summation of individual 2D materials have confirmed the successful establishment of the vertical 2D crystal hetero-structure. After transferring the WS2/MoS2 film onto a SiO2/Si substrate with pre-patterned source/drain electrodes, a bottom-gate transistor is fabricated. Compared with the transistor with only MoS2 channels, the higher drain currents of the device with the WS2/MoS2 hetero-structure have exhibited that with the introduction of 2D crystal hetero-structures, superior device performance can be obtained. The results have revealed the potential of this growth technique for the practical application of 2D crystals.

Through the sulfurization of pre-deposited transition metals, large-area and vertical 2D crystal hetero-structures can be fabricated. The film transferring and device fabrication procedures are also demonstrated in this report.

硫化过渡金属膜制备大面积垂直2D 晶体杂化结构

We have demonstrated that through the sulfurization of transition metal films such as molybdenum (Mo) and tungsten (W), large-area and uniform transition ...

Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser

The goal of this protocol is to present how to perform spin- and angle-resolved photoemission spectroscopy combined with polarization-variable 7-eV laser (laser-SARPES), and demonstrate a power of this technique for studying solid state physics. Laser-SARPES achieves two great capabilities. Firstly, by examining orbital selection rule of linearly polarized lasers, orbital selective excitation can be carried out in SAPRES experiment. Secondly, the technique can show full information of a variation of the spin quantum axis as a function of the light polarization. To demonstrate the power of the collaboration of these capabilities in laser-SARPES, we apply this technique for the investigations of spin-orbit coupled surface states of Bi2Se3. This technique affords to decompose spin and orbital components from the spin-orbit coupled wavefunctions. Moreover, as a representative advantage of using the direct spin detection collaborated with the polarization-variable laser, the technique unambiguously visualizes the light polarization dependence of the spin quantum axis in three-dimension. Laser-SARPES dramatically increases a capability of photoemission technique.

Here, we combine polarization-variable 7-eV laser with spin- and angle-resolved photoemission technique to visualize the spin-orbital coupling effect in solid states.

自旋角分辨光电子光谱与偏振变激光相结合的实验方法

The goal of this protocol is to present how to perform spin- and angle-resolved photoemission spectroscopy combined with polarization-variable 7-eV laser ...

Fabricating Reactive Surfaces with Brush-like and Crosslinked Films of Azlactone-Functionalized Block Co-Polymers

In this paper, fabrication methods that generate novel surfaces using the azlactone-based block co-polymer, poly (glycidyl methacrylate)-block-poly (vinyl dimethyl azlactone) (PGMA-b-PVDMA), are presented. Due to the high reactivity of azlactone groups towards amine, thiol, and hydroxyl groups, PGMA-b-PVDMA surfaces can be modified with secondary molecules to create chemically or biologically functionalized interfaces for a variety of applications. Previous reports of patterned PGMA-b-PVDMA interfaces have used traditional top-down patterning techniques that generate non-uniform films and poorly controlled background chemistries. Here, we describe customized patterning techniques that enable precise deposition of highly uniform PGMA-b-PVDMA films in backgrounds that are chemically inert or that have biomolecule-repellent properties. Importantly, these methods are designed to deposit PGMA-b-PVDMA films in a manner that completely preserves azlactone functionality through each processing step. Patterned films show well-controlled thicknesses that correspond to polymer brushes (~90 nm) or to highly crosslinked structures (~1-10 &#956;m). Brush patterns are generated using either the parylene lift-off or interface directed assembly methods described and are useful for precise modulation of overall chemical surface reactivity by adjusting either the PGMA-b-PVDMA pattern density or the length of the VDMA block. In contrast, the thick, crosslinked PGMA-b-PVDMA patterns are obtained using a customized micro-contact printing technique and offer the benefit of higher loading or capture of secondary material due to higher surface area to volume ratios. Detailed experimental steps, critical film characterizations, and trouble-shooting guides for each fabrication method are discussed.

Surface fabrication methods for patterned deposition of nanometer thick brushes or micron thick, crosslinked films of an azlactone block co-polymer are reported. Critical experimental steps, representative results, and limitations of each method are discussed. These methods are useful for creating functional interfaces with tailored physical features and tunable surface reactivity.

Azlactone 功能块共聚物的刷状和交联膜制备反应表面

In this paper, fabrication methods that generate novel surfaces using the azlactone-based block co-polymer, poly (glycidyl methacrylate)-block-poly (vinyl ...