Research is carried out at the Center for Functional Nanomaterials, Brookhaven National Laboratory, which is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. DE-SC0012704.

Caution: Please consult all relevant material safety data sheets (MSDS) before use. Nanomaterials may have additional hazards compared to their bulk counterpart. Please use all appropriate safety practices when handling nanomaterial-covered substrates, including the use of engineering controls (fume hood) and personal protective equipment (safety glasses, gloves, lab coat, full length pants, closed-toe shoes).
1. Preparatory Work
<ol>
	<li>Preparation of vapor deposition system
	<ol>
		<li>Vent the deposition ch...

<ol>
	<li>Hu, J. T., Odom, T. W., Lieber, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemistry+and+physics+in+one+dimension:+Synthesis+and+properties+of+nanowires+and+nanotubes.">Chemistry and physics in one dimension: Synthesis and properties of nanowires and nanotubes.</a> Acc. Chem. Res. 32, 435-445 (1999).</li><li>Akimov, A. V., 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=Generation+of+single+optical+plasmons+in+metallic+nanowires+coupled+to+quantum+dots.">Generation of single optical plasmons in metallic nanowires coupled to quantum dots.</a> Nature. 450, 402-406 (2007).</li><li>Thurn-Albrecht, T., 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=Ultrahigh-density+nanowire+arrays+grown+in+self-assembled+diblock+copolymer+templates.">Ultrahigh-density nanowire arrays grown in self-assembled diblock copolymer templates.</a> Science. 290, 2126-2129 (2000).</li><li>Xia, Y. N., 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-dimensional+nanostructures:+Synthesis,+characterization,+and+applications.">One-dimensional nanostructures: Synthesis, characterization, and applications.</a> Adv. Mater. 15, 353-389 (2003).</li><li>Gudiksen, M. S., Lauhon, L. J., Wang, J., Smith, D. C., Lieber, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+of+nanowire+superlattice+structures+for+nanoscale+photonics+and+electronics.">Growth of nanowire superlattice structures for nanoscale photonics and electronics.</a> Nature. 415, 617-620 (2002).</li><li>Yang, P. D., 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=Controlled+growth+of+ZnO+nanowires+and+their+optical+properties.">Controlled growth of ZnO nanowires and their optical properties.</a> Adv. Funct. Mater. 12, 323-331 (2002).</li><li>Allen, J. E., 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=High-resolution+detection+of+Au+catalyst+atoms+in+Si+nanowires.">High-resolution detection of Au catalyst atoms in Si nanowires.</a> Nature Nanotech. 3, 168-173 (2008).</li><li>Lin, Y. M., Sun, X. Z., 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=Theoretical+investigation+of+thermoelectric+transport+properties+of+cylindrical+Bi+nanowires.">Theoretical investigation of thermoelectric transport properties of cylindrical Bi nanowires.</a> Phys. Rev. B. 62, 4610-4623 (2000).</li><li>Isaacson, R. T., Williams, 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=Alfv&#233;n-Wave+propagation+in+solid-state+plasmas.+III.+Quantum+oscillations+of+the+Fermi+surface+of+bismuth.">Alfv&#233;n-Wave propagation in solid-state plasmas. III. Quantum oscillations of the Fermi surface of bismuth.</a> Phys Rev. 185, 682-688 (1969).</li><li>Sandomirskii, V. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantum+size+effect+in+a+semimetal+film.">Quantum size effect in a semimetal film.</a> Sov. Phys. JETP. 25, 101-106 (1967).</li><li>Huber, T. E., Nikolaeva, A., Gitsu, D., Konopko, L., Graf, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantum+confinement+and+surface-state+effects+in+bismuth+nanowires.">Quantum confinement and surface-state effects in bismuth nanowires.</a> Physica E. 37, 194-199 (2007).</li><li>Black, M. R., Lin, Y. M., Cronin, S. B., Rabin, O., 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=Infrared+absorption+in+bismuth+nanowires+resulting+from+quantum+confinement.">Infrared absorption in bismuth nanowires resulting from quantum confinement.</a> Phys. Rev. B. 65, 2921-2930 (2002).</li><li>Hofmann, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+surfaces+of+bismuth:+Structural+and+electronic+properties.">The surfaces of bismuth: Structural and electronic properties.</a> Prog. Surf. Sci. 81, 191-245 (2006).</li><li>Huber, T. E., 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=Confinement+effects+and+surface-induced+charge+carriers+in+Bi+quantum+wires.">Confinement effects and surface-induced charge carriers in Bi quantum wires.</a> Appl Phys Lett. 84, 1326-1328 (2004).</li><li>Huber, T. E., 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=Surface+state+band+mobility+and+thermopower+in+semiconducting+bismuth+nanowires.">Surface state band mobility and thermopower in semiconducting bismuth nanowires.</a> Phys. Rev. B. 83, 235414-23 (2011).</li><li>Dresselhaus, M. 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=.">.</a> 23, 129-140 (2003).</li><li>Cheng, Y. -. T., Weiner, A. M., Wong, C. A., Balogh, M. P., Lukitsch, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stress-induced+growth+of+bismuth+nanowires.">Stress-induced growth of bismuth nanowires.</a> Appl Phys Lett. 81, 3248-3250 (2002).</li><li>Volobuev, V. V., 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=The+mechanism+of+Bi+nanowire+growth+from+Bi/Co+immiscible+composite+thin+films.">The mechanism of Bi nanowire growth from Bi/Co immiscible composite thin films.</a> J. Nanosci. Nanotech. 12, 8624-8629 (2012).</li><li>Shim, W., 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=On-film+formation+of+Bi+nanowires+with+extraordinary+electron+mobility.">On-film formation of Bi nanowires with extraordinary electron mobility.</a> Nano Lett. 9, 18-22 (2009).</li><li>Berglund, S. P., Rettie, A. J. E., Hoang, S., Mullins, C. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Incorporation+of+Mo+and+W+into+nanostructured+BiVO4+films+for+efficient+photoelectrochemical+water+oxidation.">Incorporation of Mo and W into nanostructured BiVO4 films for efficient photoelectrochemical water oxidation.</a> Phys. Chem. Chem. Phys. 14, 7065-7075 (2012).</li><li>Liu, 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=Surface-Energy+Induced+Formation+of+Single+Crystalline+Bismuth+Nanowires+over+Vanadium+Thin+Film+at+Room+Temperature.">Surface-Energy Induced Formation of Single Crystalline Bismuth Nanowires over Vanadium Thin Film at Room Temperature.</a> Nano Lett. 14, 5630-5635 (2014).</li></ol>

The growth of bismuth nanowires is to be conducted in a physical vapor deposition system with at least two deposition sources, one for bismuth and another for vanadium. It is recommended that one of the sources is a magnetron sputtering source, for the deposition of vanadium. High vacuum is achieved by a turbomolecular pumps backed by a dry scroll pump. The vapor deposition system is equipped with a calibrated quartz crystal microbalance (QCM) for in situ thickness monitoring. The vapor deposition system has ele...

Nanowires confine the transport of charge carriers and other quasiparticles, such as photons and plasmons in one dimension. Accordingly, nanowires usually exhibit novel electrical, magnetic, optical and chemical properties, which grant them nearly infinite potential for applications in micro/nano electronics, photonics, biomedical, environmental and energy-related technologies.1,2 During the past two decades, numerous top-down and bottom-up approaches have been developed to synthesis a broad range of high quality metal or semiconductor nanowires at laboratory scale.3-6 Despite of these developments, each approach relies on certain unique properties of the final product for its success. For instance, the popular vapor-liquid-solid (VLS) method is better fit for the semiconductor materials that have higher melting points and form eutectic alloy with corresponding catalytic &#34;seeds&#34;.7 As a result, the synthesis of a nanowire material of particular interest may not be covered by existing techniques.
As a semimetal with small indirect band overlap (-38 meV at 0 K) and unusually light charge carriers, bismuth is one such example. The material behaves radically different at reduced dimension when compared to its bulk, as quantum confinement could turn bismuth nanowires or thin films into a narrow band gap semiconductor.8-12 In the meantime, the surface of bismuth forms a quasi-two-dimensional metal that is significantly more metallic than its bulk.13,14 It was shown that the surface of bismuth achieves an electron mobility of 2&#215;104 cm2 V-1 sec-1 and contributes strongly to its thermoelectric power in nanowire form.15 As such, there are significant interests on studying bismuth nanowires for electronic and in particular thermoelectric applications.12-16 However, due to bismuth&#39;s very low melting point (544 K) and readiness for oxidation, it remains a challenge to synthesis high quality and single crystalline bismuth nanowires using traditional vapor phase or solution phase techniques.
Previously, it has been reported by a few groups that single crystalline bismuth nanowires grow at low yield during vacuum deposition of bismuth thin film, which is attributed to the release of stress built into the film.17-20 Most recently, we discovered a novel technique that is based on the thermal evaporation of bismuth under high vacuum and leads to the scalable formation of single crystalline bismuth nanowires at high yield.21 Comparing to previously reported methods, the most unique feature of this technique is that the growth substrate is freshly coated with a thin layer of nanoporous vanadium prior to bismuth deposition. During the latter&#39;s thermal evaporation, bismuth vapor infiltrates into the nanoporous structure of the vanadium film and condenses there as nanodomains. Since vanadium is not wetted by condensed bismuth, the infiltrated domains are subsequently expulsed from the vanadium matrix to release their surface energy. It is the continuous expulsion of the bismuth nanodomains that forms the vertical bismuth nanowires. Since the bismuth domains are only 1-2 nm in diameters, they are subject to significant melting point suppression, which makes them nearly molten at RT. As a result, the nanowires growth proceeds with the substrate held at RT. On the other hand, as the migration of the bismuth domains is thermally activated, the length and width of the nanowires can be tuned over a wide range by simply controlling the temperature of the growth substrate. This detailed video protocol is intended to help new practitioners in the field avoid various common problems associated with physical vapor deposition of thin films in a high vacuum, oxygen-free environment.

<table>
	<tbody>
		<tr>
			<td>Bismuth&#160;</td>
			<td>Sigma-Aldrich</td>
			<td>556130</td>
			<td>Granular, 99.999%</td>
		</tr>
		<tr>
			<td>Vanadium Slug</td>
			<td>Alfa Aesar</td>
			<td>42829</td>
			<td>3.175mm (0.125in) dia x 6.35mm (0.25in) length, 99.8%&#160;</td>
		</tr>
		<tr>
			<td>Vanadium Sputtering Target</td>
			<td>Kurt J. Lesker</td>
			<td>EJTVXXX253A2</td>
			<td>3.00&#34; Dia. x 0.125&#34; Thick, 99.5%</td>
		</tr>
		<tr>
			<td>Acetone</td>
			<td>Sigma-Aldrich</td>
			<td>179124</td>
			<td>&#62;99.5%</td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>Alfa Aesar</td>
			<td>33361</td>
			<td>Anhydrous</td>
		</tr>
		<tr>
			<td>Silicon Wafer</td>
			<td>University Wafers</td>
			<td></td>
			<td>300 microns in thickness, (100) orientation</td>
		</tr>
		<tr>
			<td>Silver Filled Epoxy</td>
			<td>Circuit Works</td>
			<td>CW2400</td>
			<td>Two part conductive epoxy resin</td>
		</tr>
		<tr>
			<td>Tungsten Boat, Alumina Coated</td>
			<td>R. D. Mathis</td>
			<td>S9B-AO-W</td>
			<td>For bismuth thermal evaporation</td>
		</tr>
		<tr>
			<td>Tungsten Boat</td>
			<td>R. D. Mathis</td>
			<td>S4-.015W</td>
			<td>For vanadium thermal evaporation</td>
		</tr>
		<tr>
			<td>RIE Plasma</td>
			<td>Nordson March</td>
			<td>CS-1701</td>
			<td></td>
		</tr>
		<tr>
			<td>PVD 75 Vapor Deposition Platform</td>
			<td>Kurt J. Lesker</td>
			<td>PEDP75FTCLT001</td>
			<td>Equipped with three thermal evaporation source and one DC magnetron sputtering source</td>
		</tr>
		<tr>
			<td>Thermoelectric Temperature Controller</td>
			<td>LairdTech</td>
			<td>MTTC-1410</td>
			<td></td>
		</tr>
		<tr>
			<td>PT1000 RGD</td>
			<td>LairdTech</td>
			<td>340912-01</td>
			<td>Temperature sensor for MTTC-1410</td>
		</tr>
		<tr>
			<td>Thermoelectric Module</td>
			<td>LairdTech</td>
			<td>56910-502</td>
			<td></td>
		</tr>
		<tr>
			<td>Ultrasonicator</td>
			<td>Crest Ultrasonics</td>
			<td>Tru-Sweep 175</td>
			<td></td>
		</tr>
	</tbody>
</table>

seedless growth of bismuth nanowire array via vacuum thermal evaporation

Here a seedless and template-free technique is demonstrated to scalably grow bismuth nanowires, through thermal evaporation in high vacuum at RT. Conventionally reserved for the fabrication of metal thin films, thermal evaporation deposits bismuth into an array of vertical single crystalline nanowires over a flat thin film of vanadium held at RT, which is freshly deposited by magnetron sputtering or thermal evaporation. By controlling the temperature of the growth substrate the length and width of the nanowires can be tuned over a wide range. Responsible for this novel technique is a previously unknown nanowire growth mechanism that roots in the mild porosity of the vanadium thin film. Infiltrated into the vanadium pores, the bismuth domains (~ 1 nm) carry excessive surface energy that suppresses their melting point and continuously expels them out of the vanadium matrix to form nanowires. This discovery demonstrates the feasibility of scalable vapor phase synthesis of high purity nanomaterials without using any catalysts.

The cross-sectional SEM images of vanadium underlayers formed by magnetron sputtering and thermal evaporation methods are presented in Figure 2. Scanning electron microscopy (SEM) images are presented for bismuth nanowires formed at different substrate temperatures (Figure 3). The crystal structure of the bismuth nanowires is determined through transmission electron microscopy (TEM), selective area electron diffraction (SAED), and X-ray diffraction (XRD) studies (Figure 4</strong...

Watch this Scientific Journal Video about Seedless Growth of Bismuth Nanowire Array via Vacuum Thermal Evaporation at JoVE.com

Seedless Growth of Bismuth Nanowire Array via Vacuum Thermal Evaporation

A protocol for seedless and high yield growth of bismuth nanowire arrays through vacuum thermal evaporation technique is presented.

Here a seedless and template-free technique is demonstrated to scalably grow bismuth nanowires, through thermal evaporation in high vacuum at RT. ...

seedless-growth-bismuth-nanowire-array-via-vacuum-thermal

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8.3K vistas.  Brookhaven National Laboratory. A protocol for seedless and high yield growth of bismuth nanowire arrays through vacuum thermal evaporation technique is presented. 