Name: Niobium Oxide Films Deposited by Reactive Sputtering: Effect of Oxygen Flow Rate (Video) | JoVE Journal
Uploaded: 2019-09-28T14:30:00.000+00:00
Duration: 8 min 23 s
Description: Discover reactive sputtering for depositing niobium oxide films with controlled oxygen flow rates. This method produces homogeneous electron transport layers to enhance perovskite solar cell performance.

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5 minutes

The work was supported by Funda&#231;&#227;o de Amparo &#224; Pesquisa do Estado de S&#227;o Paulo (FAPESP), Centro de&#160;Desenvolvimento de Materiais Cer&#226;micos (CDMF- FAPESP&#160;N&#186; 2013/07296-2, 2017/11072-3, 2013/09963-6 and 2017/18916-2). Special thanks to Professor M&#225;ximo Siu Li for PL measurements.

1. Etching and cleaning the substrate
<ol>
	<li>Using a glass cutting system, form 2.5 x 2.5 cm substrates of fluoride thin oxide (FTO).</li>
	<li>Protect part of the substrate surface with a thermal tape leaving 0.5 cm of one side exposed.</li>
	<li>Deposit a small amount of zinc powder (enough to cover the area to be etched) on the top of the exposed FTO and drop concentrated hydrochloric acid (HCl) on the zinc powder slowly until all zinc powder is consumed by the reaction. Immediately after, rinse the substrate with deionized (DI) water. 
	CAUTION: Hydrogen gas in abundance is generated from zinc and HCl reaction.</li>
	<li>Remove the tape and wash with DI water and soap using a small brush. 
	NOTE: The brush helps to remove some residual glue from the tape.</li>
	<li>Leave the etched substrate in a soap solution (50% in water) and keep it for 15 min in an ultrasonicate bath. Then, sonicate for 15 min in DI water (2 times), followed by 10 more min in acetone and finally 10 min in isopropyl alcohol. Dry the substrate with nitrogen gas.</li>
</ol>
2. Deposition of niobium oxide films
<ol>
	<li>Fix the substrate through a shadow mask protecting 0.5 cm of both sides. 
	NOTE: On the side where the FTO was etched, it is important to certify that the FTO is covered in order to prevent short circuits when building the cell.</li>
	<li>Introduce the substrate into the sputtering chamber and seal the chamber.</li>
	<li>Start the mechanic pump. In the first 10 min, change the 3-way valve into roughing position to heat its oil and release water to improve the pumping. The primary pump works alone until the pressure is 6 x 10-2 Torr.</li>
	<li>Change the 3-way valve to backing position, and turn the turbo molecular pump on. Once the molecular pump is started, open the gate valve at the vacuum pump entry. Deposition starts when the pressure reaches 3 x 10-6 torr. 
	NOTE: Before starting the molecular pump, the primary vacuum should be better than 6 x 10-2 torr, however, not higher than 5 x 10-2 torr in order to prevent contaminating the chamber with pump oil.</li>
	<li>When the vacuum reaches 5 x 10-5 torr, open the water cooler system and turn on the substrate heating system. Set the temperature at 500 &#176;C. Increase the temperature slowly, 100 &#176;C every 5 min until it reaches the desired value.</li>
	<li>Set the gases parameters to be used in the deposition: argon of 40 sccm and oxygen of 3 to 10 sccm. 
	NOTE: The oxygen flow rate was varied in each deposition: 3, 3.5, 4 and 10 sccm. Oxygen reacts with niobium forming niobium oxide.</li>
	<li>Introduce argon onto the chamber, and set the pressure to 5 x 10-3 torr and the radio frequency (RF) to 120 W. Turn the RF on and tune using the impedance matching box. In case the plasma does not start, increase the pressure slowly until it reaches 2 x 10-2 Torr. In this pressure, the plasma should start. Set the pressure using a gate valve that can be opened or closed to change the pumping rate.</li>
	<li>Keep the plasma at 120 W for 10 min to clean the niobium target removing any oxide layer present in its surface. 
	NOTE: While cleaning the target, the substrate shutter is kept closed to protect the substrate from any material deposition.</li>
	<li>Introduce oxygen into the chamber,&#160;after stabilization, set the radio frequency power to 240 W and&#160;open the substrate shutter. Deposition starts. Set the deposition time to have a final thickness of 100 nm based on previous studies that determined the deposition rate. For each deposition condition a different deposition rate is expected, so the deposition time does also differ.</li>
	<li>Once the deposition time is completed, close the shutter immediately, turn the RF off, the close the gases and decrease the substrate temperature to room temperature.</li>
	<li>As the substrate temperature reaches room temperature, introduce air to reestablish the ambient pressure and open the chamber.. 
	NOTE: Generally, the system takes 4 h to reach a temperature of 40 &#176;C.</li>
</ol>
3. Constructing the solar cells
<ol>
	<li>Preparing the solutions used to construct the devices
	<ol>
		<li>TiO2 paste solution: Mix 150 mg of TiO2 paste in 1 mL of DI water. Stir it for 1 day before use. 
		NOTE: Keep the suspension stirring even when you are not using it to be sure that the suspension is always homogeneous.</li>
		<li>Prepare the lead iodide solution (PbI2) by mixing 420 mg of PbI2 in 1 mL of anhydrous dimethylformamide. Use only anhydrous solvents.</li>
		<li>Prepare the methylammonium iodide (CH3NH3I) solution by adding 8 mg of CH3NH3I in 1 mL of isopropyl alcohol (IPA). 
		NOTE: The water content in IPA must be less than 0.0005%.</li>
	</ol>
	</li>
	<li>Deposit TiO2 mesoporous layer on top of the niobium oxide layer using a spin coater at 4,000 rpm for 30 s.</li>
	<li>Put the substrate on the oven following the steps: 270 &#176;C for 30 min; 370 &#176;C for 30 min and 500 &#176;C for 1 h. Wait until the oven reaches room temperature and remove the substrate. 
	NOTE: The heat treatment decomposes the organic part of the paste leaving a porous layer over the film.</li>
	<li>Deposit two layers of PbI2 on top of the TiO2 mesoporous using a spin coater at 6,000 rpm for 90 s and after each deposition put the substrate in a hot plate at 70 &#176;C for 10 min. 
	NOTE: The PbI2 deposition must be inside a glove box filled with pure nitrogen or argon and with controlled atmosphere (water and oxygen &#60; 0.1 ppm).</li>
	<li>Deposit the CH3NH3I solution. Drop 0.3 mL of CH3NH3I solution onto PbI2, wait 20 s and then spin at 4,000 rpm for 30 s. Put the substrate on a hot plate at 100 &#176;C for 10 min. 
	NOTE: The CH3NH3I deposition must be inside a glove box. The total amount of CH3NH3I solution must be dropped quickly in only one step.</li>
	<li>Deposit Spiro-OMeTAD solution on top of the perovskite layer by spin coating at 4,000 rpm for 30 s. Leave the substrate in an oxygen atmosphere overnight. 
	NOTE: The Spiro-OMeTAD deposition must be inside of a glove box. After the deposition, it is important to leave the substrate overnight in an oxygen atmosphere in order to oxidize the Spiro- OMeTAD increasing its conductivity.</li>
	<li>Evaporate 70 nm of gold contact using a shadow mask at a rate of 0.2 A/s until 5 nm is reached and then increase the rate to 1 A/s. 
	NOTE: It is important to use a slow rate at the beginning to prevent gold diffusion through the cell.</li>
</ol>

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<li>Chen, W. -C., Peng, C. Y., Chang, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Heteroepitaxial+growth+of+TiN+film+on+MgO+%28100%29+by+reactive+magnetron+sputtering%5BTitle%5D)+AND+%22Nanoscale+Research+Letters%22%5BJournal%5D)">Heteroepitaxial growth of TiN film on MgO (100) by reactive magnetron sputtering.</a> Nanoscale Research Letters. 9, 551(2014).</li>
<li>Guo, Q. X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Heteroepitaxial+growth+of+gallium+nitride+on+%28+1+1+1+%29+GaAs+substrates+by+radio+frequency+magnetron+sputtering%5BTitle%5D)+AND+%22Journal+of+Crystal+Growth%22%5BJournal%5D)">Heteroepitaxial growth of gallium nitride on ( 1 1 1 ) GaAs substrates by radio frequency magnetron sputtering.</a> Journal of Crystal Growth. 239, 1079-1083 (2002).</li>
<li>Berg, S., Nyberg, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Fundamental+understanding+and+modeling+of+reactive+sputtering+processes%5BTitle%5D)+AND+%22Thin+Solid+films%22%5BJournal%5D)">Fundamental understanding and modeling of reactive sputtering processes.</a> Thin Solid films. (476), 215-230 (2005).</li>
<li>Wong, M. S., Sproul, W. D., Chu, X., Barnett, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Reactive+magnetron+sputter+deposition+of+niobium+nitride+films%5BTitle%5D)+AND+%22Journal+Vacuum+Science+%26+Technology+A%3A+Vacuum%2C+Surfaces+and+Films%22%5BJournal%5D)">Reactive magnetron sputter deposition of niobium nitride films.</a> Journal Vacuum Science & Technology A: Vacuum, Surfaces and Films. 11, 1528-1533 (2002).</li>
<li>Zoita, C. N., Braic, L., Kiss, A., Braic, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Characterization+of+NbC+coatings+deposited+by+magnetron+sputtering+method%5BTitle%5D)+AND+%22Surface+and+Coatings+Technology%22%5BJournal%5D)">Characterization of NbC coatings deposited by magnetron sputtering method.</a> Surface and Coatings Technology. 204, 2002-2005 (2010).</li>
<li>Nico, C., Monteiro, T., Graça, M. P. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Niobium+oxides+and+niobates+physical+properties%3A+Review+and+prospects%5BTitle%5D)+AND+%22Progress+in+Materials+Science%22%5BJournal%5D)">Niobium oxides and niobates physical properties: Review and prospects.</a> Progress in Materials Science. 80, 1-37 (2016).</li>
<li>Aegerter, M. A., Schmitt, M., Guo, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Sol-gel+niobium+pentoxide+coatings%3A+Applications+to+photovoltaic+energy+conversion+and+electrochromism%5BTitle%5D)+AND+%22International+Journal+of+Photoenergy%22%5BJournal%5D)">Sol-gel niobium pentoxide coatings: Applications to photovoltaic energy conversion and electrochromism.</a> International Journal of Photoenergy. 4, 1-10 (2002).</li>
<li>Fernandes, S. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Hysteresis+dependence+on+CH3NH3PbI3+deposition+method+in+perovskite+solar+cells%5BTitle%5D)+AND+%22Proceedings+of+SPIE+-+International+Society+for+Optics+and+Photonics%22%5BJournal%5D)">Hysteresis dependence on CH3NH3PbI3 deposition method in perovskite solar cells.</a> Proceedings of SPIE - International Society for Optics and Photonics. 9936, 9936(2016).</li>
<li>Fernandes, S. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Nb2O5hole+blocking+layer+for+hysteresis-free+perovskite+solar+cells%5BTitle%5D)+AND+%22Materials+Letters%22%5BJournal%5D)">Nb2O5hole blocking layer for hysteresis-free perovskite solar cells.</a> Materials Letters. 181, 103-107 (2016).</li>
<li>Hamada, K., Murakami, N., Tsubota, T., Ohno, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Solution-processed+amorphous+niobium+oxide+as+a+novel+electron+collection+layer+for+inverted+polymer+solar+cells%5BTitle%5D)+AND+%22Chemical+Physics+Letters%22%5BJournal%5D)">Solution-processed amorphous niobium oxide as a novel electron collection layer for inverted polymer solar cells.</a> Chemical Physics Letters. 586, 81-84 (2013).</li>
<li>Aegerter, M. a <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Sol-gel+niobium+pentoxide%3A+A+promising+material+for+electrochromic+coatings%2C+batteries%2C+nanocrystalline+solar+cells+and+catalysis%5BTitle%5D)+AND+%22Solar+Energy+Materials+and+Solar+Cells%22%5BJournal%5D)">Sol-gel niobium pentoxide: A promising material for electrochromic coatings, batteries, nanocrystalline solar cells and catalysis.</a> Solar Energy Materials and Solar Cells. 68, 401-422 (2001).</li>
<li>Rani, R. A., Zoolfakar, A. S., O'Mullane, A. P., Austin, M. W., Kalantar-Zadeh, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Thin+films+and+nanostructures+of+niobium+pentoxide%3A+fundamental+properties%2C+synthesis+methods+and+applications%5BTitle%5D)+AND+%22Journal+Materials+Chemistry+A%22%5BJournal%5D)">Thin films and nanostructures of niobium pentoxide: fundamental properties, synthesis methods and applications.</a> Journal Materials Chemistry A. 2, 15683-15703 (2014).</li>
<li>Foroughi-Abari, A., Cadien, K. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Growth%2C+structure+and+properties+of+sputtered+niobium+oxide+thin+films%5BTitle%5D)+AND+%22Thin+Solid+Films%22%5BJournal%5D)">Growth, structure and properties of sputtered niobium oxide thin films.</a> Thin Solid Films. 519, 3068-3073 (2011).</li>
<li>Numata, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Nb-doped+amorphous+titanium+oxide+compact+layer+for+formamidinium-based+high+efficiency+perovskite+solar+cells+by+low-temperature+fabrication%5BTitle%5D)+AND+%22Journal+Materials+Chemistry+A%22%5BJournal%5D)">Nb-doped amorphous titanium oxide compact layer for formamidinium-based high efficiency perovskite solar cells by low-temperature fabrication.</a> Journal Materials Chemistry A. 6, 9583-9591 (2018).</li>
<li>Graça, M. P. F., Meireles, A., Nico, C., Valente, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Nb2O5+nanosize+powders+prepared+by+sol-gel+-+Structure%2C+morphology+and+dielectric+properties%5BTitle%5D)+AND+%22Journal+of+Alloys+and+Compounds%22%5BJournal%5D)">Nb2O5 nanosize powders prepared by sol-gel - Structure, morphology and dielectric properties.</a> Journal of Alloys and Compounds. 553, 177-182 (2013).</li>
<li>Kogo, A., Numata, Y., Ikegami, M., Miyasaka, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Nb+2+O+5+Blocking+Layer+for+High+Open-circuit+Voltage+Perovskite+Solar+Cells%5BTitle%5D)+AND+%22Chemistry+Letters%22%5BJournal%5D)">Nb 2 O 5 Blocking Layer for High Open-circuit Voltage Perovskite Solar Cells.</a> Chemistry Letters. 44, 829-830 (2015).</li>
<li>Ueno, S., Fujihara, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Effect+of+an+Nb2O5+nanolayer+coating+on+ZnO+electrodes+in+dye-sensitized+solar+cells%5BTitle%5D)+AND+%22Electrochimica+Acta%22%5BJournal%5D)">Effect of an Nb2O5 nanolayer coating on ZnO electrodes in dye-sensitized solar cells.</a> Electrochimica Acta. 56, 2906-2913 (2011).</li>
<li>Fernandes, S. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Exploring+the+Properties+of+Niobium+Oxide+Films+for+Electron+Transport+Layers+in+Perovskite+Solar+Cells%5BTitle%5D)+AND+%22Frontiers+in+Chemistry%22%5BJournal%5D)">Exploring the Properties of Niobium Oxide Films for Electron Transport Layers in Perovskite Solar Cells.</a> Frontiers in Chemistry. 7, 1-9 (2019).</li>
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</ol>

The authors have nothing to disclose.

The niobium oxide films prepared in this work was used as electron transport layer in perovskite solar cells. The most important characteristic required for an electron transport layer is to prevent recombination, blocking holes and transferring efficiently electrons.
In this respect the use of reactive sputtering technique is advantageous since it produces dense and compact films. Also, as already mentioned, compared to sol-gel, anodization, hydrothermal, and chemical vapor deposition synthes...

The sputtering technique is widely used to deposit high-quality films. Its main application is in the semiconductor industry, although it is also used in surface coating for improvement in mechanical properties, and reflective layers1. The main advantage of sputtering is the possibility to deposit different materials over different substrates; the good reproducibility and control over the deposition parameters. The sputtering technique allows deposition of homogeneous films, with good adhesion over large areas and at low-cost when compared with other deposition methods like chemical vapor deposition (CVD), molecular beam epitaxy (MBE) and atomic layer deposition (ALD)1,2. Commonly, semiconductor films deposited by sputtering are amorphous or polycrystalline, however, there are some reports on epitaxial growth by sputtering3,4. Nevertheless, the sputtering process is highly complex and the range of the parameter is wide5, so in order to achieve high-quality films, a good comprehension of the process and parameter optimization is necessary for each material.
There are several articles reporting on the deposition of niobium oxide films by sputtering, as well as niobium nitride6 and niobium carbide7. Among Nb-oxides, niobium pentoxide (Nb2O5) is a transparent, air-stable and water-insoluble material that exhibits extensive polymorphism. It is an n-type semiconductor with band gap values ranging from 3.1 to 5.3 eV, giving these oxides a wide range of applications8,9,10,11,12,13,14,15,16,17,18,19. Nb2O5 has attracted considerable attention as a promising material to be used in perovskite solar cells due to its comparable electron injection efficiency and better chemical stability compared to titanium dioxide (TiO2). In addition, the band gap of Nb2O5 could improve the open-circuit voltage (Voc) of the cells14.
In this work, Nb2O5 was deposited by reactive sputtering under different oxygen flow rates. At low oxygen flow rates, the conductivity of the films were increased without making use of doping, which introduces impurities on the system. These films were used as electron transport layer in perovskite solar cells improving the performance of these cells. It was found that decreasing the amount of oxygen induces the formation of oxygen vacancies, which increases the conductivity of the films leading to solar cells with better efficiency.

<table><tbody><tr><td>2-propanol</td><td>Merck</td><td>67-63-0</td><td>solvent with maximum of 0.005% H&lt;sub&gt;2&lt;/sub&gt;O</td></tr><tr><td>4-tert-butylpyridine</td><td>Sigma Aldrich</td><td>3978-81-2</td><td>chemical with 96% purity</td></tr><tr><td>acetonitrile</td><td>Sigma Aldrich</td><td>75-05-8</td><td>anhydrous solvent , 99.8% purity</td></tr><tr><td>bis(trifluoromethane)sulfonimide lithium salt</td><td>Sigma Aldrich</td><td>90076-65-6</td><td>chemical with &amp;ge;99.95% purity</td></tr><tr><td>chlorobenzene</td><td>Sigma Aldrich</td><td>108-90-7</td><td>anhydrous solvent , 99.8% purity</td></tr><tr><td>ethanol</td><td>Sigma Aldrich</td><td>200-578-6</td><td>solvent</td></tr><tr><td>Fluorine doped tin oxide (SnO2:F) glass substrate</td><td>Solaronix</td><td>TCO22-7/LI</td><td>substrate to deposit films</td></tr><tr><td>Kaptom tape</td><td>Usinainfo</td><td>04227</td><td>thermal tape used to cover the substrates</td></tr><tr><td>Kurt J Lesker magnetron sputtering system</td><td>Kurt J Lesker</td><td>------</td><td>Sputtering equipment used to deposit compact films</td></tr><tr><td>Lead (II) iodide</td><td>Alfa Aesar</td><td>10101-63-0</td><td>PbI&lt;sub&gt;2&lt;/sub&gt; salt- 99.998% purity</td></tr><tr><td>methylammonium iodide</td><td>Dyesol</td><td>14965-49-2</td><td>CH&lt;sub&gt;3&lt;/sub&gt;NH&lt;sub&gt;3&lt;/sub&gt;I salt</td></tr><tr><td>N&lt;sup&gt;2&lt;/sup&gt;,N&lt;sup&gt;2&lt;/sup&gt;,N&lt;sup&gt;2&amp;prime;&lt;/sup&gt;,N&lt;sup&gt;2&amp;prime;&lt;/sup&gt;,N&lt;sup&gt;7&lt;/sup&gt;,N&lt;sup&gt;7&lt;/sup&gt;,N&lt;sup&gt;7&amp;prime;&lt;/sup&gt;,N&lt;sup&gt;7&amp;prime;&lt;/sup&gt;-octakis (4-methoxyphenyl)-9,9&amp;prime;-spirobi [9H-fluorene]-2,2&amp;prime;,7,7&amp;prime;-tetramine</td><td>Sigma Aldrich</td><td>207739-72-8</td><td>Spiro-OMeTAD salt, 99% purity</td></tr><tr><td>Niobium target of 3&amp;rdquo;</td><td>CBMM- Brazilian Metallurgy and Mining Company</td><td>------</td><td>niobium sputtering target used in the sputtering system</td></tr><tr><td>N-N dimethylformamide</td><td>Merck</td><td>68-12-2</td><td>solvent with maximum of 0.003% H&lt;sub&gt;2&lt;/sub&gt;O</td></tr><tr><td>TiO&lt;sub&gt;2&lt;/sub&gt; paste</td><td>Dyesol</td><td>DSL 30NR-D</td><td>titanium dioxide paste</td></tr><tr><td>tris(2-(1H-pyrazol-1-yl)-4-tert-butylpyridine)cobalt(III) tri[bis(trifluoromethane)sulfonimide]</td><td>Dyesol</td><td>329768935</td><td>FK 209 Co(III) TFSL salt</td></tr></tbody></table>

niobium oxide films deposited by reactive sputtering: effect of oxygen flow rate

Niobium Oxide Films Deposited by Reactive Sputtering: Effect of Oxygen Flow Rate

Reactive sputtering is a versatile technique used to form compact films with excellent homogeneity. In addition, it allows easy control over deposition parameters such as gas flow rate that results in changes on composition and thus in the film required properties. In this report, reactive sputtering is used to deposit niobium oxide films. A niobium target is used as metal source and different oxygen flow rates to deposit niobium oxide films. The oxygen flow rate was changed from 3 to 10 sccm. The films deposited under low oxygen flow rates show higher electrical conductivity and provide better perovskite solar cells when used as electron transport layer.

In the sputtering system, the deposition rate is strongly influenced by the oxygen flow rate. The deposition rate decreases when the oxygen flow is increased. Considering the present conditions of the target area used and plasma power, it is observed that from 3 to 4 sccm there is an expressive decrease on the deposition rate, however, when the oxygen is increased from 4 to 10 sccm it becomes less pronounced. In the regime of 3 sccm the deposition rate is 1.1 nm/s, decreasing abruptly to 0.1 nm/s for 10 sccm as seen in <...

Here, we present a protocol for niobium oxide films deposition by reactive sputtering with different oxygen flow rates for use as an electron transport layer in perovskite solar cells.

Reactive sputtering is a versatile technique used to form compact films with excellent homogeneity. In addition, it allows easy control over deposition ...

niobium-oxide-films-deposited-reactive-sputtering-effect-oxygen-flow

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The synthesis of high quality bulk and thin film (Mg0.25(1-x)CoxNi0.25(1-x)Cu0.25(1-x)Zn0.25(1-x))O and (Mg0.25(1-x)Co0.25(1-x)Ni0.25(1-x)CuxZn0.25(1-x))O entropy-stabilized oxides is presented.

Bulk and Thin Film Synthesis of Compositionally Variant Entropy-stabilized Oxides

Here, we present a protocol to grow LSMO nanoparticles and (Gd) BCO films on (001) SrTiO3 (STO) single-crystal substrates by radio frequency (RF)-sputtering.

Radio Frequency Magnetron Sputtering of GdBa2Cu3O7&#8722;&#948;/ La0.67Sr0.33MnO3 Quasi-bilayer Films on SrTiO3 (STO) Single-crystal Substrates

Oxide materials show many exotic properties that can be controlled by tuning the oxygen content. Here, we demonstrate the tuning of oxygen content in oxides by varying the pulsed laser deposition parameters and by performing postannealing. As an example, electronic properties of SrTiO3-based heterostructures are tuned by growth modifications and annealing.

Tuning Oxide Properties by Oxygen Vacancy Control During Growth and Annealing

This protocol presents the preparation of U2O5 thin films obtained in situ under ultra-high vacuum. The process involves oxidation and reduction of UO2 films with atomic oxygen and atomic hydrogen, respectively.

U2O5 Film Preparation via UO2 Deposition by Direct Current Sputtering and Successive Oxidation and Reduction with Atomic Oxygen and Atomic Hydrogen

This article describes the growth of epitaxial films of Mg3N2 and Zn3N2 on MgO substrates by plasma-assisted molecular beam epitaxy with N2 gas as the nitrogen source and optical growth monitoring.

Plasma-Assisted Molecular Beam Epitaxy Growth of Mg3N2 and Zn3N2 Thin Films

Discover reactive sputtering for depositing niobium oxide films with controlled oxygen flow rates. This method produces homogeneous electron transport layers to enhance perovskite solar cell performance.

Niobium Oxide Films Deposited by Reactive Sputtering: Effect of Oxygen Flow Rate

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