Systematic Study of the SiOx Film with Different Stoichiometry by Plasma-Enhanced Atomic Layer Deposition and Its Application in SiOx/SiO2 Super-Lattice

Atomic scale control of the thickness of thin film makes atomic layer deposition highly advantageous in the preparation of high quality super-lattices. However, precisely controlling the film chemical stoichiometry is very challenging. In this study, we deposited SiOx film with different stoichiometry by plasma enhanced atomic layer deposition. After reviewing various deposition parameters like temperature, precursor pulse time, and gas flow, the silicon dioxides of stoichiometric (SiO2) and non-stoichiometric (SiO1.8 and SiO1.6) were successfully fabricated. X-ray photo-electron spectroscopy was first employed to analyze the element content and chemical bonding energy of these films. Then the morphology, structure, composition, and optical characteristics of SiOx film were systematically studied through atomic force microscope, transmission electron microscopy, X-ray reflection, and spectroscopic ellipsometry. The experimental results indicate that both the mass density and refractive index of SiO1.8 and SiO1.6 are less than SiO2 film. The energy band-gap is approved by spectroscopic ellipsometry data and X-ray photo-electron spectroscopy O 1s analysis. The results demonstrate that the energy band-gap decreases as the oxygen concentration decreases in SiOx film. After we obtained the Si-rich silicon oxide film deposition, the SiO1.6/SiO2 super-lattices was fabricated and its photoluminescence (PL) property was characterized by PL spectra. The weak PL intensity gives us greater awareness that more research is needed in order to decrease the x of SiOx film to a larger extent through further optimizing plasma-enhanced atomic layer deposition processes, and hence improve the photoluminescence properties of SiOx/SiO2 super-lattices.

Download Full-text

Air Annealing Effect on Oxygen Vacancy Defects in Al-doped ZnO Films Grown by High-Speed Atmospheric Atomic Layer Deposition

Molecules ◽

10.3390/molecules25215043 ◽

2020 ◽

Vol 25 (21) ◽

pp. 5043

Author(s):

Chia-Hsun Hsu ◽

Xin-Peng Geng ◽

Wan-Yu Wu ◽

Ming-Jie Zhao ◽

Xiao-Ying Zhang ◽

...

Keyword(s):

Atomic Layer Deposition ◽

Band Gap ◽

Photoelectron Spectroscopy ◽

High Speed ◽

Oxygen Vacancies ◽

Annealing Temperature ◽

Atomic Layer ◽

Zno Films ◽

X Ray ◽

Layer Deposition

In this study, aluminum-doped zinc oxide (Al:ZnO) thin films were grown by high-speed atmospheric atomic layer deposition (AALD), and the effects of air annealing on film properties are investigated. The experimental results show that the thermal annealing can significantly reduce the amount of oxygen vacancies defects as evidenced by X-ray photoelectron spectroscopy spectra due to the in-diffusion of oxygen from air to the films. As shown by X-ray diffraction, the annealing repairs the crystalline structure and releases the stress. The absorption coefficient of the films increases with the annealing temperature due to the increased density. The annealing temperature reaching 600 °C leads to relatively significant changes in grain size and band gap. From the results of band gap and Hall-effect measurements, the annealing temperature lower than 600 °C reduces the oxygen vacancies defects acting as shallow donors, while it is suspected that the annealing temperature higher than 600 °C can further remove the oxygen defects introduced mid-gap states.

Download Full-text

X-ray reflectometry and spectroscopic ellipsometry characterization of Al2O3 atomic layer deposition on HF-last and NH3 plasma pretreatment Si substrates

Journal of Materials Research ◽

10.1557/jmr.2007.0184 ◽

2007 ◽

Vol 22 (5) ◽

pp. 1214-1218 ◽

Cited By ~ 3

Author(s):

Hong-Liang Lu ◽

Min Xu ◽

Shi-Jin Ding ◽

Wei Chen ◽

David Wei Zhang ◽

...

Keyword(s):

Atomic Layer Deposition ◽

Film Thickness ◽

Spectroscopic Ellipsometry ◽

Atomic Layer ◽

Si Substrate ◽

Interfacial Film ◽

X Ray ◽

Si Substrates ◽

Layer Deposition ◽

Plasma Pretreatment

Al2O3 films are grown by atomic layer deposition (ALD) using trimethylaluminum and water as precursors on HF-last and NH3 plasma pretreatment Si substrates. The thickness, surface roughness, and density of Al2O3 films as well as the nature of their interlayers with Si substrates are characterized by x-ray reflectivity and spectroscopic ellipsometry techniques. The growth rates of Al2O3 films are 1.1 Å/cycle and 1.3 Å/cycle, respectively, on HF-last and NH3-plasma-nitrided surfaces. Al2O3 layer densities are rather independent of the number of growth cycles in all cases. The interfacial film thickness increases with the number of ALD cycles when deposited on an HF-last Si substrate. However, because SiOxNy inhibits oxygen diffusion, the interfacial film thickness is independent of the number of ALD cycles on the nitrided Si substrate.

Download Full-text

One-Dimensional TiO2@GaON Core-Shell Nanowires with Controlled Shell Thickness from Atomic Layer Deposition for Stable and Efficient Photoelectrochemical Water Splitting

10.26434/chemrxiv.9199796 ◽

2019 ◽

Author(s):

Jiajia Tao ◽

Hong-Ping Ma ◽

Kaiping Yuan ◽

Yang Gu ◽

Jianwei Lian ◽

...

Keyword(s):

Atomic Layer Deposition ◽

Band Gap ◽

Water Splitting ◽

Atomic Layer ◽

Photoelectrochemical Water Splitting ◽

Core Shell ◽

Photoelectrochemical Performance ◽

Highly Efficient ◽

Layer Deposition ◽

Shell Nanowires

<div>As a promising oxygen evolution reaction semiconductor, TiO2 has been extensively investigated for solar photoelectrochemical water splitting. Here, a highly efficient and stable strategy for rationally preparing GaON cocatalysts on TiO2 by atomic layer deposition is demonstrated, which we show significantly enhances the</div><div>photoelectrochemical performance compared to TiO2-based photoanodes. For TiO2@20 nm-GaON core-shell nanowires a photocurrent density up to 1.10 mA cm-2 (1.23 V vs RHE) under AM 1.5 G irradiation (100 mW cm-2) has been achieved, which is 14 times higher than that of TiO2 NWs. Furthermore, the oxygen vacancy formation on GaON as well as the band gap matching with TiO2 not only provides more active sites for water oxidation but also enhances light absorption to promote interfacial charge separation and migration. Density functional theory studies of model systems of GaON-modified TiO2 confirm the band gap reduction, high reducibility and ability to activate water. The highly efficient and stable systems of TiO2@GaON core-shell nanowires provide a deeper understanding and universal strategy for enhancing photoelectrochemical performance of photoanodes now available. </div>

Download Full-text

Ex-situ X-ray diffraction analysis of electrode strain at TiO2 atomic layer deposition/α-MoO3 interface in a novel aqueous potassium ion battery

Journal of Power Sources ◽

10.1016/j.jpowsour.2016.03.064 ◽

2016 ◽

Vol 316 ◽

pp. 160-169 ◽

Cited By ~ 27

Author(s):

Nicholas David Schuppert ◽

Santanu Mukherjee ◽

Alex M. Bates ◽

Eun-Jin Son ◽

Moon Jong Choi ◽

...

Keyword(s):

Atomic Layer Deposition ◽

Diffraction Analysis ◽

Atomic Layer ◽

Potassium Ion ◽

Ex Situ ◽

X Ray Diffraction ◽

X Ray ◽

Layer Deposition

Download Full-text

Energy Band Gap Studies of CdS Nanomaterials

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.3.97 ◽

2008 ◽

Vol 3 ◽

pp. 97-102 ◽

Cited By ~ 17

Author(s):

Dinu Patidar ◽

K.S. Rathore ◽

N.S. Saxena ◽

Kananbala Sharma ◽

T.P. Sharma

Keyword(s):

Optical Absorption ◽

Band Gap ◽

Energy Band ◽

Chemical Method ◽

Optical Absorption Spectroscopy ◽

Cds Nanoparticles ◽

X Ray Diffraction ◽

Energy Band Gap ◽

X Ray ◽

Simple Chemical

The CdS nanoparticles of different sizes are synthesized by a simple chemical method. Here, CdS nanoparticles are grown through the reaction of solution of different concentration of CdCl2 with H2S. X-ray diffraction pattern confirms nano nature of CdS and has been used to determine the size of particle. Optical absorption spectroscopy is used to measure the energy band gap of these nanomaterials by using Tauc relation. Energy band gap ranging between 3.12 eV to 2.47 eV have been obtained for the samples containing the nanoparticles in the range of 2.3 to 6.0 nm size. A correlation between the band gap and size of the nanoparticles is also established.

Download Full-text

Investigation on the Preparation of High Precision Multilayer X-ray Fresnel Zone Plates Based on Atomic Layer Deposition Technology

ACTA PHOTONICA SINICA ◽

10.3788/gzxb20215001.0123001 ◽

2021 ◽

Vol 50 (1) ◽

pp. 156-164

Author(s):

吴鹿杰 Lujie WU ◽

文庆涛 Qingtao WEN ◽

高雅增 Yazeng GAO ◽

卢维尔 Weier LU ◽

夏洋 Yang XIA ◽

...

Keyword(s):

Atomic Layer Deposition ◽

High Precision ◽

Fresnel Zone ◽

Atomic Layer ◽

Fresnel Zone Plates ◽

X Ray ◽

Zone Plates ◽

Layer Deposition ◽

Deposition Technology

Download Full-text

In Situ Synchrotron X-Ray Diffraction Analysis of Phase Transformation in Epitaxial Metastable hcp Nickel Thin Films, Prepared via Plasma-Enhanced Atomic Layer Deposition

Advanced Materials Interfaces ◽

10.1002/admi.201800957 ◽

2018 ◽

Vol 5 (24) ◽

pp. 1800957 ◽

Cited By ~ 1

Author(s):

Pouyan Motamedi ◽

Ken Bosnick ◽

Ken Cadien ◽

James D. Hogan

Keyword(s):

Thin Films ◽

Phase Transformation ◽

Atomic Layer Deposition ◽

Diffraction Analysis ◽

Atomic Layer ◽

X Ray Diffraction ◽

X Ray ◽

Nickel Thin Films ◽

Layer Deposition

Download Full-text

Effect of Dopant Concentration on the Structural, Optical and Sensing Properties of (SnO2)1-x(TiO2:CuO)x Sprayed Films

Baghdad Science Journal ◽

10.21123/bsj.2019.16.2.0361 ◽

2019 ◽

Vol 16 (2) ◽

pp. 0361

Author(s):

Mahmood Et al.

Keyword(s):

Optical Properties ◽

Band Gap ◽

Energy Band ◽

Spray Pyrolysis Technique ◽

Single Crystal Silicon ◽

Dielectric Constants ◽

Energy Band Gap ◽

Crystal Silicon ◽

X Ray ◽

Regular Manner

Spray pyrolysis technique was subjected to synthesized (SnO2)1-x (TiO2: CuO) x Thin films on different substrates like glass and single crystal silicon using. The structure of the deposited films was studied using x-ray diffraction. A more pronounced diffraction peaks of SnO2 while no peaks of (CuO , TiO2 ) phase appear in the X-ray profiles by increasing of the content of (TiO2 , CuO) in the sprayed films. Mixing concentration (TiO2 , CuO) influences on the size of the crystallites of the SnO2 films ,the size of crystallites of the spray paralyzed oxide films change in regular manner by increasing of (TiO2 , CuO) amount. The effect of mixing concentration on the optical properties of the films was also investigated. The reflectance and transmittance spectra in the wavelength range (300-1100) nm were employed to determine the optical properties such as energy band gap (Eg) and refractive index (n), extinction coefficient (k) , real and imaginary parts of dielectric constants (ε1, ε2) for (SnO2)1-x(TiO2:CuO)x films. The energy band gap omit of which showed reduction from (3.65 to 2.2) eV by reducing of SnO2 amount from (100 to 70) % .The reduction of energy band gap was ascribed to the new tail states introduced in the band gap of tin oxide. The sensitivity of the prepared sensor film was determined resistance difference of the films when exposed to oxidizing gas. The data declared that the mixed SnO2 films have better sensitivity in comparison with unmixed films.

Download Full-text

Atomic layer deposition triggered Fe-In-S cluster and gradient energy band in ZnInS photoanode for improved oxygen evolution reaction

Nature Communications ◽

10.1038/s41467-021-25609-0 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Linxing Meng ◽

Jinlu He ◽

Xiaolong Zhou ◽

Kaimo Deng ◽

Weiwei Xu ◽

...

Keyword(s):

Atomic Layer Deposition ◽

Oxygen Evolution ◽

Oxygen Evolution Reaction ◽

Energy Band ◽

High Performance ◽

Carrier Transport ◽

Atomic Layer ◽

Onset Potential ◽

Layer Deposition ◽

Gradient Energy

AbstractVast bulk recombination of photo-generated carriers and sluggish surface oxygen evolution reaction (OER) kinetics severely hinder the development of photoelectrochemical water splitting. Herein, through constructing a vertically ordered ZnInS nanosheet array with an interior gradient energy band as photoanode, the bulk recombination of photogenerated carriers decreases greatly. We use the atomic layer deposition technology to introduce Fe-In-S clusters into the surface of photoanode. First-principles calculations and comprehensive characterizations indicate that these clusters effectively lower the electrochemical reaction barrier on the photoanode surface and promote the surface OER reaction kinetics through precisely affecting the second and third steps (forming processes of O* and OOH*) of the four-electron reaction. As a result, the optimal photoanode exhibits the high performance with a significantly enhanced photocurrent of 5.35 mA cm−2 at 1.23 VRHE and onset potential of 0.09 VRHE. Present results demonstrate a robust platform for controllable surface modification, nanofabrication, and carrier transport.

Download Full-text