Name: graphene-assisted quasi-van der waals epitaxy of aln film on nano-patterned sapphire substrate for ultraviolet light emitting diodes
Uploaded: 2020-06-25T12:30:00
Description: Watch this Scientific Journal Video about Graphene-Assisted Quasi-van der Waals Epitaxy of AlN Film on Nano-Patterned Sapphire Substrate for Ultraviolet Light Emitting Diodes at JoVE.com

This work was financially supported by the National Key R&#38;D Program of China (No. 2018YFB0406703), the National Natural Science Foundation of China (Nos. 61474109, 61527814, 11474274, 61427901), and the Beijing Natural Science Foundation (No. 4182063)

CAUTION: Several of the chemicals used in these methods are acutely toxic and carcinogenic. Please consult all relevant material safety data sheets (MSDS) before use.
1. Preparation of NPSS by nanoimprint lithography (NIL)
<ol>
	<li>Deposition of SiO2 film
	<ol>
		<li>Wash the 2&#34;&#160;c-plane flat sapphire substrate with ethanol followed by deionized water three times.</li>
		<li>Dry the substrate with a nitrogen gun.</li>
		<li>Deposit 200 nm SiO2 film on the flat ...

<ol>
	<li>Sakai, 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=Demonstration+of+AlGaN-Based+Deep-Ultraviolet+Light-Emitting+Diodes+on+High-Quality+AlN+Templates.">Demonstration of AlGaN-Based Deep-Ultraviolet Light-Emitting Diodes on High-Quality AlN Templates.</a> Jappanese Journal of Applied Physics. 49, 022102 (2010).</li><li>Yun, J., Hirayama, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Investigation+of+the+light-extraction+efficiency+in+280+nm+AlGaN-based+light-emitting+diodes+having+a+highly+transparent+p-AlGaN+layer.">Investigation of the light-extraction efficiency in 280 nm AlGaN-based light-emitting diodes having a highly transparent p-AlGaN layer.</a> Journal of Applied Physics. 121, 013105 (2017).</li><li>Khan, A., Balakrishnan, K., Katona, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultraviolet+light-emitting+diodes+based+on+group+three+nitrides.">Ultraviolet light-emitting diodes based on group three nitrides.</a> Nature Photonics. 2, 77-84 (2008).</li><li>Balushi, Z. Y. 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=The+impact+of+graphene+properties+on+GaN+and+AlN+nucleation.">The impact of graphene properties on GaN and AlN nucleation.</a> Surface Science. 634, 81-88 (2015).</li><li>Motoki, 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=Growth+and+characterization+of+freestanding+GaN+substrates.">Growth and characterization of freestanding GaN substrates.</a> Journal of Crystal Growth. 237, 912-921 (2002).</li><li>Kim, 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=Remote+epitaxy+through+graphene+enables+two-dimensional+material-based+layer+transfer.">Remote epitaxy through graphene enables two-dimensional material-based layer transfer.</a> Nature. 544, 340-343 (2017).</li><li>Hemmingsson, C., Pozina, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimization+of+low+temperature+GaN+buffer+layers+for+halide+vapor+phase+epitaxy+growth+of+bulk+GaN.">Optimization of low temperature GaN buffer layers for halide vapor phase epitaxy growth of bulk GaN.</a> Journal of Crystal Growth. 366, 61-66 (2013).</li><li>Chen, Z., 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-Brightness+Blue+Light-Emitting+Diodes+Enabled+by+a+Directly+Grown+Graphene+Buffer+Layer.">High-Brightness Blue Light-Emitting Diodes Enabled by a Directly Grown Graphene Buffer Layer.</a> Advanced Materials. 30, 1801608 (2018).</li><li>Dong, 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=282-nm+AlGaN-based+deep+ultraviolet+light-emitting+diodes+with+improved+performance+on+nano-patterned+sapphire+substrates.">282-nm AlGaN-based deep ultraviolet light-emitting diodes with improved performance on nano-patterned sapphire substrates.</a> Applied Physics Letters. 102, 241113 (2013).</li><li>Imura, 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=Epitaxial+lateral+overgrowth+of+AlN+on+trench-patterned+AlN+layers.">Epitaxial lateral overgrowth of AlN on trench-patterned AlN layers.</a> Journal of Crystal Growth. 298, 257-260 (2007).</li><li>Kueller, 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=Growth+of+AlGaN+and+AlN+on+patterned+AlN/sapphire+templates.">Growth of AlGaN and AlN on patterned AlN/sapphire templates.</a> Journal of Crystal Growth. 315, 200-203 (2011).</li><li>Kneissl, 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=Advances+in+group+III-nitride-based+deep+UV+light-emitting+diode+technology.">Advances in group III-nitride-based deep UV light-emitting diode technology.</a> Semiconductor Science &amp; Technology. 26, 014036 (2010).</li><li>Kunook, C., Chul-Ho, L., Gyu-Chul, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transferable+GaN+layers+grown+on+ZnO-coated+graphene+layers+for+optoelectronic+devices.">Transferable GaN layers grown on ZnO-coated graphene layers for optoelectronic devices.</a> Science. 330, 655-657 (2010).</li><li>Kim, J., 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=Principle+of+direct+van+der+Waals+epitaxy+of+single-crystalline+films+on+epitaxial+graphene.">Principle of direct van der Waals epitaxy of single-crystalline films on epitaxial graphene.</a> Nature Communications. 5, 4836 (2014).</li><li>Han, 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=Improved+heat+dissipation+in+gallium+nitride+light-emitting+diodes+with+embedded+graphene+oxide+pattern.">Improved heat dissipation in gallium nitride light-emitting diodes with embedded graphene oxide pattern.</a> Nature Communications. 4, 1452 (2013).</li><li>Gupta, 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=MOVPE+growth+of+semipolar+III-nitride+semiconductors+on+CVD+graphene.">MOVPE growth of semipolar III-nitride semiconductors on CVD graphene.</a> Journal of Crystal Growth. 372, 105-108 (2013).</li><li>Heinke, H., Kirchner, V., Einfeldt, S., Hommel, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=X-ray+diffraction+analysis+of+the+defect+structure+in+epitaxial+GaN.">X-ray diffraction analysis of the defect structure in epitaxial GaN.</a> Appllied Physics Letters. 77, 2145-2147 (2000).</li><li>Lughi, V., Clarke, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Defect+and+Stress+Characterization+of+AlN+Films+by+Raman+Spectroscopy.">Defect and Stress Characterization of AlN Films by Raman Spectroscopy.</a> Appllied Physics Letters. 89, 2653 (2006).</li><li>Li, 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=Van+der+Waals+epitaxy+of+GaN-based+light-emitting+diodes+on+wet-transferred+multilayer+graphene+film.">Van der Waals epitaxy of GaN-based light-emitting diodes on wet-transferred multilayer graphene film.</a> Jappanese Journal of Applied Physics. 56, 085506 (2017).</li><li>Chang, 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=Graphene-assisted+quasi-van+der+Waals+epitaxy+of+AlN+film+for+ultraviolet+light+emitting+diodes+on+nano-patterned+sapphire+substrate.">Graphene-assisted quasi-van der Waals epitaxy of AlN film for ultraviolet light emitting diodes on nano-patterned sapphire substrate.</a> Applled Physics Letters. 114, 091107 (2019).</li></ol>

As shown in Figure 1A, the NPSS prepared by the NIL technique illustrates the nano-concave cone patterns with 400 nm depth, 1 &#956;m period of pattern, and 300 nm width of the unetched regions. After the APCVD growth of graphene layer, the graphene-NPSS is shown in Figure 1B. The significant increased D peak of N-plasma treated graphene in Raman spectra Figure 1C demonstrates the i...

AlN and AlGaN are the most essential materials in DUV-LEDs1,2, which have been widely used in various fields such as sterilization, polymer curing, biochemical detection, non-line-of-sight communication, and special lighting3. Due to the lack of intrinsic substrates, AlN heteroepitaxy on sapphire substrates by MOCVD has become the most common technical route4. However, the large lattice mismatch between AlN and sapphire substrate leads to stress accumulation5,6, high density dislocations, and stacking faults7. Thus, the internal quantum efficiency of LEDs are reduced8. In recent decades, using patterned sapphire as substrates (PSS) to induce AlN epitaxial lateral overgrowth (ELO) has been proposed to solve this problem. In addition, great progress has been made in the growth of AlN templates9,10,11. However, with a high surface adhesion coefficient and bonding energy (2.88 eV for AlN), Al atoms have low atomic surface mobility, and the growth of AlN tends to have a three-dimensional island growth mode12. Thus, the epitaxial growth of AlN films on NPSS is difficult and requires higher coalescence thickness (over 3 &#956;m) than that on flat sapphire substrates, which causes longer growth time and requires high costs9.
Recently, graphene shows great potential for use as a buffer layer for AlN growth due to its hexagonal arrangement of sp2 hybridized carbon atoms13. In addition, the quasi-van der Waals epitaxy (QvdWE) of AlN on graphene may reduce the mismatch effect and has paved a new way for AlN growth14,15. To increase the chemical reactivity of graphene, Chen et al. used N2-plasma treated graphene as a buffer layer and determined the QvdWE of high quality AlN and GaN films8, which demonstrates the utilization of graphene as a buffer layer.
Combining the N2-plasma treated graphene technic with commercial NPSS substrates, this protocol presents a new method for quick growth and coalescence of AlN on a graphene-NPSS substrate. The completely coalesce thickness of AlN on graphene-NPSS is confirmed to be less than 1 &#181;m, and the epitaxial AlN layers are of high quality and stress-released. This method paves a new way for AlN template mass production and shows great potential in the application of AlGaN-based DUV-LEDs.

<table>
	<tbody>
		<tr>
			<td>Acetone,99.5%</td>
			<td>Bei Jing Tong Guang Fine Chemicals company</td>
			<td>1090</td>
			<td></td>
		</tr>
		<tr>
			<td>APCVD</td>
			<td>Linderberg</td>
			<td>Blue M</td>
			<td></td>
		</tr>
		<tr>
			<td>EB</td>
			<td>AST</td>
			<td>Peva-600E</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethonal,99.7%</td>
			<td>Bei Jing Tong Guang Fine Chemicals company</td>
			<td>1170</td>
			<td></td>
		</tr>
		<tr>
			<td>HF,40%</td>
			<td>Beijing Chemical Works</td>
			<td>1789</td>
			<td></td>
		</tr>
		<tr>
			<td>ICP-RIE</td>
			<td>AST</td>
			<td>Cirie-200</td>
			<td></td>
		</tr>
		<tr>
			<td>MOCVD</td>
			<td>VEECO</td>
			<td>P125</td>
			<td></td>
		</tr>
		<tr>
			<td>PECVD</td>
			<td>Oerlikon</td>
			<td>790+</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate,85%</td>
			<td>Beijing Chemical Works</td>
			<td>1805</td>
			<td></td>
		</tr>
		<tr>
			<td>Sulfuric acid,98%</td>
			<td>Beijing Chemical Works</td>
			<td>10343</td>
			<td></td>
		</tr>
	</tbody>
</table>

graphene-assisted quasi-van der waals epitaxy of aln film on nano-patterned sapphire substrate for ultraviolet light emitting diodes

This protocol demonstrates a method for graphene-assisted quick growth and coalescence of AlN on nano-pattened sapphire substrate (NPSS). Graphene layers are directly grown on NPSS using catalyst-free atmospheric-pressure chemical vapor deposition (APCVD). By applying nitrogen reactive ion etching (RIE) plasma treatment, defects are introduced into the graphene film to enhance chemical reactivity. During metal-organic chemical vapor deposition (MOCVD) growth of AlN, this N-plasma treated graphene buffer enables AlN quick growth, and coalescence on NPSS is confirmed by cross-sectional scanning electron microscopy (SEM). The high quality of AlN on graphene-NPSS is then evaluated by X-ray rocking curves (XRCs) with narrow (0002) and (10-12) full width at half-maximum (FWHM) as 267.2 arcsec and 503.4 arcsec, respectively. Compared to bare NPSS, AlN growth on graphene-NPSS shows significant reduction of residual stress from 0.87 GPa to 0.25 Gpa, based on Raman measurements. Followed by AlGaN multiple quantum wells (MQWS) growth on graphene-NPSS, AlGaN-based deep ultraviolet light-emitting-diodes (DUV LEDs) are fabricated. The fabricated DUV-LEDs also demonstrate obvious, enhanced luminescence performance. This work provides a new solution for the growth of high quality AlN and fabrication of high performance DUV-LEDs using a shorter process and less costs.

Scanning electron microscopy (SEM) images, X-ray diffraction rocking curves (XRC), Raman spectra, transmission electron microscopy (TEM) images, and electroluminescence (EL) spectrum were collected for the epitaxial AlN film (Figure 1, Figure 2) and AlGaN-based DUV-LEDs (Figure 3). The SEM and TEM are used to determine the morphology of the AlN on graphene-NPSS. XRD and Raman are used to calculate the dislocation densities and the r...

Watch this Scientific Journal Video about Graphene-Assisted Quasi-van der Waals Epitaxy of AlN Film on Nano-Patterned Sapphire Substrate for Ultraviolet Light Emitting Diodes at JoVE.com

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

A protocol for graphene-assisted growth of high-quality AlN films on nano-patterned sapphire substrate is presented.

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

Research

JoVE Journal

Engineering

Polycrystalline Silicon Thin-film Solar cells with Plasmonic-enhanced Light-trapping

One of major approaches to cheaper solar cells is reducing the amount of semiconductor material used for their fabrication and making cells thinner. To ...

Fabrication of White Light-emitting Electrochemical Cells with Stable Emission from Exciplexes

The authors present an approach for fabricating stable white light emission from polymer light-emitting electrochemical cells (PLECs) having an active ...

Plasma-assisted Molecular Beam Epitaxy of N-polar InAlN-barrier High-electron-mobility Transistors

Plasma-assisted molecular beam epitaxy is well suited for the epitaxial growth of III-nitride thin films and heterostructures with smooth, abrupt ...

Production and Characterization of Vacuum Deposited Organic Light Emitting Diodes

A method for producing simple and efficient thermally-activated delayed fluorescence organic light-emitting diodes (OLEDs) based on guest-host or exciplex ...

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

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

Enhanced Electron Injection and Exciton Confinement for Pure Blue Quantum-Dot Light-Emitting Diodes by Introducing Partially Oxidized Aluminum Cathode

Stable and efficient red (R), green (G), and blue (B) light sources based on solution-processed quantum dots (QDs) play important roles in next-generation ...

Film Control to Study Contributions of Waves to Droplet Impact Dynamics on Thin Flowing Liquid Films

Droplet impact is a very common phenomenon in nature and attracts attention due to its aesthetic fascination and wide-ranging applications. Previous ...

Synchrotron X-ray Microdiffraction and Fluorescence Imaging of Mineral and Rock Samples

In this report, we describe a detailed procedure for acquiring and processing&#160;x-ray microfluorescence (&#956;XRF), and Laue and powder ...

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 ...

Measurement of Dynamic Force Acted on Water Strider Leg Jumping Upward by the PVDF Film Sensor

This study aimed to make an explanation for the phenomenon in nature that water strider usually jumps or glides on the water surface easily but quickly, ...