Name: fabricating van der waals heterostructures with precise rotational alignment
Uploaded: 2019-07-05T13:00:00
Description: Watch this Scientific Journal Video about Fabricating van der Waals Heterostructures with Precise Rotational Alignment at JoVE.com

作者承认渥太华大学和NSERC发现资助RGPIN-2016-06717和NSERCSPG QC2DM的资助。

1. 传输程序的仪器
<ol><li>为了可视化传输过程,使用可在明场照明下操作的光学显微镜。由于 2D 晶体的典型尺寸为 1~500 μm2,因此显微镜配有 5 倍、50 倍和 100 倍的长工作距离目标。显微镜还必须配备连接到计算机的照相机 (图 1a)。</li>
	<li>使用单独的操纵器单独控制两个即将堆叠的晶体的位置。采用计算机可编程和控制的操纵器,以尽量减少传输过程中的振动。 注:...

<ol>
	<li>Novoselov, K. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electric+Field+Effect+in+Atomically+Thin+Carbon+Films.">Electric Field Effect in Atomically Thin Carbon Films.</a> Science. 306 (5696), 666 (2004).</li><li>Novoselov, K. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two-dimensional+atomic+crystals.">Two-dimensional atomic crystals.</a> Proceedings of the National Academy of Sciences of the United States of America. 102 (30), 10451 (2005).</li><li>Zhang, Y., Tan, Y. -. W., Stormer, H. L., Kim, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+observation+of+the+quantum+Hall+effect+and+Berry&#39;s+phase+in+graphene.">Experimental observation of the quantum Hall effect and Berry&#39;s phase in graphene.</a> Nature. 438, 201 (2005).</li><li>Geim, A. K., Van Grigorieva, I. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Van+der+Waals+heterostructures.">Van der Waals heterostructures.</a> Nature. 499, 419 (2013).</li><li>Song, J. C. W., Gabor, N. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electron+quantum+metamaterials+in+van+der+Waals+heterostructures.">Electron quantum metamaterials in van der Waals heterostructures.</a> Nature Nanotechnology. 13 (11), 986-993 (2018).</li><li>Jin, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrafast+dynamics+in+van+der+Waals+heterostructures.">Ultrafast dynamics in van der Waals heterostructures.</a> Nature Nanotechnology. 13 (11), 994-1003 (2018).</li><li>Rivera, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interlayer+valley+excitons+in+heterobilayers+of+transition+metal+dichalcogenides.">Interlayer valley excitons in heterobilayers of transition metal dichalcogenides.</a> Nature Nanotechnology. 13 (11), 1004-1015 (2018).</li><li>Lu, C. -. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Local,+global,+and+nonlinear+screening+in+twisted+double-layer+graphene.">Local, global, and nonlinear screening in twisted double-layer graphene.</a> Proceedings of the National Academy of Sciences of the United States of America. , 201606278 (2016).</li><li>Luican-Mayer, A., Li, G., Andrei, E. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Atomic+scale+characterization+of+mismatched+graphene+layers.">Atomic scale characterization of mismatched graphene layers.</a> Journal of Electron Spectroscopy and Related Phenomena. 219, 92-98 (2017).</li><li>Frisenda, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+progress+in+the+assembly+of+nanodevices+and+van+der+Waals+heterostructures+by+deterministic+placement+of+2D+materials.">Recent progress in the assembly of nanodevices and van der Waals heterostructures by deterministic placement of 2D materials.</a> Chemical Society Reviews. 47 (1), 53-68 (2018).</li><li>Ribeiro-Palau, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Twistable+electronics+with+dynamically+rotatable+heterostructures.">Twistable electronics with dynamically rotatable heterostructures.</a> Science. 361 (6403), 690-693 (2018).</li><li>Kim, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=van+der+Waals+Heterostructures+with+High+Accuracy+Rotational+Alignment.">van der Waals Heterostructures with High Accuracy Rotational Alignment.</a> Nano Letters. 16 (3), 1989-1995 (2016).</li><li>Cao, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unconventional+superconductivity+in+magic-angle+graphene+superlattices.">Unconventional superconductivity in magic-angle graphene superlattices.</a> Nature. 556 (7699), 43 (2018).</li><li>Luican, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-layer+behavior+and+its+breakdown+in+twisted+graphene+layers.">Single-layer behavior and its breakdown in twisted graphene layers.</a> Physical review letters. 106 (12), 126802 (2011).</li><li>Li, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Observation+of+Van+Hove+singularities+in+twisted+graphene+layers.">Observation of Van Hove singularities in twisted graphene layers.</a> Nature Physics. 6 (2), 109 (2010).</li><li>Castellanos-Gomez, A., van der Zant, H. S. J., Steele, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Folded+MoS2+layers+with+reduced+interlayer+coupling.">Folded MoS2 layers with reduced interlayer coupling.</a> Nano Research. 7 (4), 572-578 (2014).</li><li>van der Zande, A. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tailoring+the+Electronic+Structure+in+Bilayer+Molybdenum+Disulfide+via+Interlayer+Twist.">Tailoring the Electronic Structure in Bilayer Molybdenum Disulfide via Interlayer Twist.</a> Nano Letters. 14 (7), 3869-3875 (2014).</li><li>Huang, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Probing+the+Interlayer+Coupling+of+Twisted+Bilayer+MoS2+Using+Photoluminescence+Spectroscopy.">Probing the Interlayer Coupling of Twisted Bilayer MoS2 Using Photoluminescence Spectroscopy.</a> Nano Letters. 14 (10), 5500-5508 (2014).</li><li>Liu, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolution+of+interlayer+coupling+in+twisted+molybdenum+disulfide+bilayers.">Evolution of interlayer coupling in twisted molybdenum disulfide bilayers.</a> Nature Communications. 5, 4966 (2014).</li><li>Cao, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Correlated+insulator+behaviour+at+half-filling+in+magic-angle+graphene+superlattices.">Correlated insulator behaviour at half-filling in magic-angle graphene superlattices.</a> Nature. 556, 80 (2018).</li><li>. Tuning superconductivity in twisted bilayer graphene Available from: <a target="_blank" href="https://arxiv.org/abs/1808.07865">https://arxiv.org/abs/1808.07865</a> (2018)</li><li>Blake, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Making+graphene+visible.">Making graphene visible.</a> Applied Physics Letters. 91 (6), 063124 (2007).</li><li>Lin, Y. -. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-Layer+ReS2:+Two-Dimensional+Semiconductor+with+Tunable+In-Plane+Anisotropy.">Single-Layer ReS2: Two-Dimensional Semiconductor with Tunable In-Plane Anisotropy.</a> ACS Nano. 9 (11), 11249-11257 (2015).</li><li>Chenet, D. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In-Plane+Anisotropy+in+Mono-+and+Few-Layer+ReS2+Probed+by+Raman+Spectroscopy+and+Scanning+Transmission+Electron+Microscopy.">In-Plane Anisotropy in Mono- and Few-Layer ReS2 Probed by Raman Spectroscopy and Scanning Transmission Electron Microscopy.</a> Nano Letters. 15 (9), 5667-5672 (2015).</li><li>Masubuchi, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autonomous+robotic+searching+and+assembly+of+two-dimensional+crystals+to+build+van+der+Waals+superlattices.">Autonomous robotic searching and assembly of two-dimensional crystals to build van der Waals superlattices.</a> Nature Communications. 9 (1), 1413 (2018).</li><li>Ling, X., Wang, H., Huang, S., Xia, F., Dresselhaus, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+renaissance+of+black+phosphorus.">The renaissance of black phosphorus.</a> Proceedings of the National Academy of Sciences of the United States of America. 112 (15), 4523-4530 (2015).</li><li>Huang, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Layer-dependent+ferromagnetism+in+a+van+der+Waals+crystal+down+to+the+monolayer+limit.">Layer-dependent ferromagnetism in a van der Waals crystal down to the monolayer limit.</a> Nature. 546, 270 (2017).</li><li>Kim, H. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=One+Million+Percent+Tunnel+Magnetoresistance+in+a+Magnetic+van+der+Waals+Heterostructure.">One Million Percent Tunnel Magnetoresistance in a Magnetic van der Waals Heterostructure.</a> Nano Letters. 18 (8), 4885-4890 (2018).</li></ol>

此处介绍的自建传输设置提供了一种使用横向和旋转控制构建新型分层材料的方法。与文献10、25中描述的其他解决方案相比,我们的系统不需要复杂的基础设施,但它达到了2D晶体受控对齐的目标。
该步骤中最关键的步骤是将顶部晶体与底部晶体对齐并放置。振动可能是对齐失败的原因,因此,必须尽量减少其影响。在这方面,此处介绍?...

在新兴的二维(2D)材料领域,研究人员开发了一种技术,使石墨烯1,2,3(原子扁平的碳原子片)从分离后开始。石墨。石墨烯是更大等级的分层二维材料的成员,也称为范德瓦尔斯材料或晶体。它们具有强共价层内粘结和弱范德瓦尔斯层间耦合。因此,从石墨中分离石墨烯的技术也可以应用于其他二维材料,其中可以打破弱层间粘结并隔离单层。该领域的一个关键发展是证明,正如范德瓦尔斯债券持有相邻的层二维材料可以打破,他们也可以放回一起2,4。因此,通过控制地堆叠具有不同属性的 2D 材料层,可以创建 2D 材质的晶体。这激起了极大的兴趣,因为以前在自然界中不存在的材料可以创造,目的是发现以前无法进入的物理现象4,5,6,7 、8、9或为技术应用开发高级设备。因此,对堆叠2D材料进行精确控制已成为10、11、12研究领域的主要目标之一。
特别是范德瓦尔斯异质结构中相邻层之间的扭曲角是控制材料特性的重要参数13。例如,在某些角度上,相邻图层之间引入相对扭曲可以有效地以电子方式使两个图层分离。这在石墨烯14,15以及过渡金属三卤基尼16,17,18,19中进行了研究。最近,令人惊讶的是,它也可以改变这些材料的物质状态。在低温下,以"神奇角度"定向的双层石墨烯在低温下充当Mott绝缘体,在电子密度适当调谐时,甚至超导体,这一发现引起了极大的兴趣,并认识到了角控制的重要性。当制造分层范德瓦尔斯异质结构13,20,21。
在通过调整层之间的相对方向来调整新型范德瓦尔材料特性的想法所开辟的科学机会的激励下,我们提出了一种自制仪器以及创建这种结构的程序与角控制。

<table>
	<tbody>
		<tr>
			<td>5X objective lens</td>
			<td>Nikon Metrology</td>
			<td>MUE12050</td>
			<td>23.5 mm working distance and 0.15 numerical aperture</td>
		</tr>
		<tr>
			<td>50X objective lens</td>
			<td>Nikon Metrology</td>
			<td>MUE21500</td>
			<td>19 mm working distance and 0.4 numerical aperture</td>
		</tr>
		<tr>
			<td>100X objective lens</td>
			<td>Nikon Metrology</td>
			<td>MUE21900</td>
			<td>4.5 mm working distance and 0.8 numerical aperture</td>
		</tr>
		<tr>
			<td>Acetone</td>
			<td>Sigma-Aldrich</td>
			<td>270725</td>
			<td>Purity &#8805;99.90%</td>
		</tr>
		<tr>
			<td>Adhesive tape</td>
			<td>Ultron Systems, Inc.</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Anisole</td>
			<td>MicroChem</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Atomic force microscope</td>
			<td>Bruker</td>
			<td>Dimension Icon</td>
			<td>We typicall use the ScanAsyst mode</td>
		</tr>
		<tr>
			<td>Bottom stage rotation manipulator</td>
			<td>Zaber Technologies</td>
			<td>X-RSW60A-PTB2</td>
			<td>360&#176; travel with step size of 4.091 &#956;rad</td>
		</tr>
		<tr>
			<td>Bottom stage X manipulator</td>
			<td>Zaber Technologies</td>
			<td>X-LSM025A-PTB2</td>
			<td>25 mm travel with step size of 47.625 nm</td>
		</tr>
		<tr>
			<td>Bottom stage Y manipulator</td>
			<td>Zaber Technologies</td>
			<td>X-LSM025A-PTB2</td>
			<td>25 mm travel with step size of 47.625 nm</td>
		</tr>
		<tr>
			<td>Bottom stage Z manipulator</td>
			<td>Zaber Technologies</td>
			<td>X-VSR40A-KX14A</td>
			<td>40 mm travel with step size of 95.25 nm</td>
		</tr>
		<tr>
			<td>Isopropanol</td>
			<td>Sigma-Aldrich</td>
			<td>563935</td>
			<td>Purity 99.999%</td>
		</tr>
		<tr>
			<td>LabVIEW software</td>
			<td>National Instruments</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Macor</td>
			<td>McMaster-Carr</td>
			<td>8489K238</td>
			<td></td>
		</tr>
		<tr>
			<td>Microscope camera</td>
			<td>Zeiss</td>
			<td>426555-0000-000</td>
			<td>5 megapixel, 47 fps live frame rate, exposure time of 100 &#956;s - 2 s, color camera</td>
		</tr>
		<tr>
			<td>Molybdenum disulfide (MoS2)</td>
			<td>HQ Graphene</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Optical breadboard</td>
			<td>Thorlabs, Inc.</td>
			<td>MB4545/M</td>
			<td></td>
		</tr>
		<tr>
			<td>Optical microscope</td>
			<td>Nikon Metrology</td>
			<td>LV150N</td>
			<td></td>
		</tr>
		<tr>
			<td>Oxygen plasma etcher</td>
			<td>Plasma Etch, Inc.</td>
			<td>PE-50</td>
			<td></td>
		</tr>
		<tr>
			<td>PDMS stamp</td>
			<td>Gel-Pak</td>
			<td>PF-20-X4</td>
			<td></td>
		</tr>
		<tr>
			<td>PMMA 950 A6</td>
			<td>MichroChem Corp.</td>
			<td>M230006 0500L1GL</td>
			<td></td>
		</tr>
		<tr>
			<td>Polypropylene carbonate</td>
			<td>Sigma-Aldrich</td>
			<td>389021-100g</td>
			<td></td>
		</tr>
		<tr>
			<td>PVA Partall #10</td>
			<td>Composites Canada</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Rhenium disulfide (ReS2)</td>
			<td>HQ Graphene</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Si/SiO2 substrate</td>
			<td>Nova Electronics Materials</td>
			<td>HS39626-OX</td>
			<td></td>
		</tr>
		<tr>
			<td>Spin coater</td>
			<td>Laurell Technologies</td>
			<td>WS-650-23</td>
			<td></td>
		</tr>
		<tr>
			<td>Temperature controller</td>
			<td>Auber Instruments</td>
			<td>SYL-23X2-24</td>
			<td>Controls the temperature of the bottom stage via a J type thermocouple</td>
		</tr>
		<tr>
			<td>Top stage controller unit</td>
			<td>Mechonics</td>
			<td>CF.030.0003</td>
			<td></td>
		</tr>
		<tr>
			<td>Top stage X manipulator</td>
			<td>Mechonics</td>
			<td>MS.030.1800</td>
			<td>18 mm travel with step size of 11 nm</td>
		</tr>
		<tr>
			<td>Top stage Y manipulator</td>
			<td>Mechonics</td>
			<td>MS.030.1800</td>
			<td>18 mm travel with step size of 11 nm</td>
		</tr>
		<tr>
			<td>Top stage Z manipulator</td>
			<td>Mechonics</td>
			<td>MS.030.3000</td>
			<td>30 mm travel with step size of 11 nm</td>
		</tr>
		<tr>
			<td>Ultrasonic bath</td>
			<td>Elma Schmidbauer GmbH</td>
			<td>Elmasonic P 30 H</td>
			<td></td>
		</tr>
	</tbody>
</table>

fabricating van der waals heterostructures with precise rotational alignment

在本作品中,我们描述了一种通过堆叠不同的超薄分层 2D 材料来创建新晶体(范德瓦尔斯异构结构)的技术。我们不仅演示横向控制,而且重要的是,还要控制相邻图层的角对齐。该技术的核心由自建传输设置表示,该装置允许用户控制传输中涉及的各个晶体的位置。这是通过亚微米(平移)和亚度(角)精度实现的。在将它们堆叠在一起之前,隔离晶体由由编程软件接口控制的定制设计移动阶段单独操作。此外,由于整个传输设置由计算机控制,用户可以远程创建精确的异质结构,而无需直接接触传输设置,将该技术标记为"免提"。除了介绍传输设置外,我们还介绍了两种用于制备随后堆叠的晶体的技术。

为了说明我们程序的结果和有效性,我们提出了一系列角度控制的二硫二铵(ReS2)薄晶体。为了强调所述方法也可以应用于原子薄层,我们还举例说明了两个相对扭曲的单层二氧化硫(MoS2)的构造。
为了演示传输设置的角度对齐功能,我们使用二硫化硫二铵 (ReS2)。由于其平面内各向异性晶格结构,这种晶体机械...

Watch this Scientific Journal Video about Fabricating van der Waals Heterostructures with Precise Rotational Alignment at JoVE.com

Fabricating van der Waals Heterostructures with Precise Rotational Alignment

在本作品中,我们描述了一种技术,该技术用于通过堆叠超薄分层 2D 材料来创建新晶体(范德瓦尔异构结构),并精确控制位置和相对方向。

使用精确旋转对齐来制造范德瓦尔斯异构结构

In this work we describe a technique for creating new crystals (van der Waals heterostructures) by stacking distinct ultrathin layered 2D materials. We ...

该协议允许创建以前不存在的材料，目的是发现以前无法接近的物理现象或为技术应用开发卓越的设备。该技术的主要优点是，设备可以在环境控制中远程操作，这可以降低手动错误的风险，还可以提高样品的清洁度。此外，系统还配备了旋转级，这允许用户在两片之间达到次度角对齐。由于我们正在处理薄晶体和小表面积，识别适当大小的薄片对未经训练的眼睛来说可能具有挑战性。此外，晶体的较小尺寸很容易导致在传输过程中错位。因此，建议您一丝不苟地执行这些步骤。协议中的许多步骤都有难以解释的特定细节，但在直观呈现时，它们要简单得多。为了可视化传输过程，利用可在亮场照明下操作的光学显微镜。为显微镜配备 5 倍、50 倍和 100 倍长工作距离目标。显微镜还必须配备连接到计算机的摄像机。装备两个独立的操纵器，如图所示，以单独控制晶体的位置。制造可支持玻璃幻灯片的定制样品支架。此样品架将用于定位顶部晶体。对于底部操纵器，将扁平加热元件放在加工玻璃陶瓷支架中，并贴在旋转级上。然后，将加热元件连接到电源和温度控制器。从充满丙酮的烧杯中从硅氧化物晶圆中淹没一厘米的正方形，然后将烧杯放入超声波清洁剂中。10 分钟后，使用一对钳子从烧杯中取出晶圆，然后用异丙醇冲洗，然后用氮气枪将晶圆干燥。接下来，小心地取出部分晶体，并将其放在一块半导体级胶带上。拿第二块胶带，用力压住固定水晶的初始胶带。剥去两块胶带，重复几次，产生许多薄薄的水晶片。用薄的 2D 晶体将胶带压在刚清洁的基材上，使晶体与基材直接接触，然后剥去胶带，将去角质的薄片留在基材上。要去除任何残留的粘合剂，请将所得样品放入装满丙酮的烧杯中。10分钟后，取出样品，用异丙醇冲洗，然后用氮气枪擦干。使用光学显微镜检查去角质薄片，通过评估剥落与基材的光学对比度来估计其厚度。然后，在攻丝模式下使用 AFM 以更好地量化表面形态并测量薄片厚度。使用附加的聚甲基丙烯酸酯薄膜将晶体去角质，为转移过程准备顶部基板。获得如前所述的清洁基材后，将基板放在旋转涂布器上，用聚乙烯醇盖住。以 3，000 RPM 旋转基板一分钟，形成厚度约 450 纳米的层。然后，将基板直接放在热板上，在 75 摄氏度下烤掉5分钟。冷却后，将基板放回旋转涂布器上，用聚甲基甲基丙烯酸酯盖住。以 1，500 RPM 的速度将一层 820 纳米厚的 PMMA 旋转到基材上一分钟。旋转涂层后，将基板放回热板上，并在 75 摄氏度下烤掉。五分钟后，从热板上取下基板，沿其边缘放置胶带片，以创建胶带框架。然后，机械地将 2D 晶体去角质到 PMMA 表面，如上一节所示。使用锋利的钳子将 PMMA 与 PVA 分离，慢慢剥回磁带框架。PMMA 层和去角质晶体以及胶带框架将从硅氧化物晶圆基板中的 PVA 中分离出来。接下来，反转磁带框架，并放在加工的支撑上，使晶体朝下。将样品放在光学显微镜下，并使用一对锋利的钳子将一个小垫圈精确放在 PMMA 薄膜上，以便其环绕所需的薄片。然后，放下玻璃滑梯，将玻璃滑轨压在外露的胶带上，将其粘附在聚合物上。将准备好的基板放在传输设置的底部阶段。在此基材上，确定所需薄片的位置。这种薄片将成为底部晶体。然后，将顶部基板放入传输设置的顶部基板支架中。使用低放大倍率目标，将底部基板聚焦到焦点，并居中所需的薄片。缓慢降低顶部基板，直到目标能够看到。然后，调整其横向位置和两片的旋转对齐方式。当薄片接近根据需要对齐时，切换到 50 倍目标，并继续降低顶部基板，同时调整薄片对齐。然后，一旦对齐，降低顶部基板，直到顶部薄片完全接触底部薄片。由于颜色的突然变化，接触是明显的。进行接触时，将底部基材加热至 75 摄氏度，以便更好地将 PMMA 粘附到底部基板。PMMA 将从玻璃幻灯片上分离。然后，清洁底部基板以去除 PMMA 薄膜。要使用薄片转移的冲压方法，首先将基板放在冲压设置的底部阶段。在此基板上，确定所需薄片的位置，即底部晶体。接下来，将顶部基板放入传输设置的支架中，将底部基板加热至 100 摄氏度。然后，对齐顶部晶体与底部薄片接触。两片片之间完全接触后，慢慢抬起顶部基板。这会导致顶部薄片从邮票跌落到底部基板。二硫化铀晶体是演示角度对齐的理想之选，因为它机械地去角质为具有明确定义的边缘的拉长条。在这里，顶部薄片被放置在一个75度角的底部晶体使用PDMS冲压方法，如本视频所示。原子力显微镜用于精确测量顶部和底部薄片之间的扭曲角度。使用 PMMA PVA 过程，成功使用传输设置创建由两个单层片组成的结构。各个单层显示在这里去角质到PMMA和硅二氧化硅。演示的程序通过光学显微镜显示的结构。可以使用 AFM 确认更多细节，例如堆叠单层的厚度和相对位置。本程序最重要的部分是薄片的横向和旋转对齐。其他的转移方法也存在，它们遵循类似的协议，不同的聚合物和二维晶体可以用来制造特定的结构。当然，还可以使用额外的清洁方法来确保原始的晶体表面和界面。当使用诸如PMMA、丙酮等化学品时，一定要穿戴适当的个人防护装备，并在通风良好的环境中（如烟罩）执行步骤。

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SCIENTISTS IN ACTION

Fabricating Metamaterials Using the Fiber Drawing Method

制造超材料使用光纤拉丝法

Metamaterials are man-made composite materials, fabricated by assembling components much smaller than the wavelength at which they operate 1. They owe ...

科研

工程学

Characterization of Nanocrystal Size Distribution using Raman Spectroscopy with a Multi-particle Phonon Confinement Model

使用拉曼光谱与多颗粒的声子坐月子型号纳米大小分布的特征

Analysis of the size distribution of nanocrystals is a critical requirement for the processing and optimization of their size-dependent properties. The ...

Growth and Electrostatic/chemical Properties of Metal/LaAlO3/SrTiO3 Heterostructures

Growth and Electrostatic/chemical Properties of Metal/LaAlO3/SrTiO3 Heterostructures

金属/LaAlO 的生长和静电/化学性质3/SrTiO3异

The quasi 2D electron system (q2DES) that forms at the interface between LaAlO3 (LAO) and SrTiO3 (STO) has attracted much attention from the oxide ...

A Fabrication and Measurement Method for a Flexible Ferroelectric Element Based on Van Der Waals Heteroepitaxy

基于范德华 Heteroepitaxy 的柔性铁电元件制备及测量方法

Flexible non-volatile memories have received much attention as they are applicable for portable smart electronic device in the future, relying on ...

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

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 ...

One-Step Approach to Fabricating Polydimethylsiloxane Microfluidic Channels of Different Geometric Sections by Sequential Wet Etching Processes

连续湿法刻蚀法制作不同几何断面烷微流控通道的一步法

Polydimethylsiloxane (PDMS) materials are substantially exploited to fabricate microfluidic devices by using soft lithography replica molding techniques. ...

Preparing an Isotopically Pure 229Th Ion Beam for Studies of 229mTh

Preparing an Isotopically Pure 229Th Ion Beam for Studies of 229mTh

为229mTh的研究准备一个同位素纯229Th Ion光束

A methodology is described to generate an isotopically pure 229Th ion beam in the 2+ and 3+ charge states. This ion beam enables one to investigate the ...

Graphene-Assisted Quasi-van der Waals Epitaxy of AlN Film on Nano-Patterned Sapphire Substrate for Ultraviolet Light Emitting Diodes

紫外发光二极管纳米图案蓝宝石基板的AlN薄膜的石墨烯辅助准范德瓦尔斯皮Taxy

This protocol demonstrates a method for graphene-assisted quick growth and coalescence of AlN on nano-pattened sapphire substrate (NPSS). Graphene layers ...

Treating Surfaces with a Cold Atmospheric Pressure Plasma using the COST-Jet

使用成本喷气机用冷大气压力等离子体处理表面

In recent years, non-thermal atmospheric pressure plasmas have been used extensively for surface treatments, in particular, due to their potential in ...

Etalon Assembly and Fiber-Etalon Alignment

Etalon Assembly and Fiber-Etalon Alignment (Video) | JoVE 

标准具组装和纤维-标准具对准