Suppression of Oxygen Vacancy Defects in sALD-ZnO Films Annealed in Different Conditions

Zinc oxide (ZnO) has drawn much attention due to its excellent optical and electrical properties. In this study, ZnO film was prepared by a high-deposition-rate spatial atomic layer deposition (ALD) and subjected to a post-annealing process to suppress the intrinsic defects and improve the crystallinity and film properties. The results show that the film thickness increases with annealing temperature owing to the increment of oxide layer caused by the suppression of oxygen vacancy defects as indicated by the X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) spectra. The film transmittance is seldom influenced by annealing. The refractive index increases with annealing temperature at 300–700 °C, possibly due to higher density and crystallinity of the film. The band gap decreases after annealing, which should be ascribed to the decrease in carrier concentration according to Burstein–Moss model. The carrier concentration decreases with increasing annealing temperature at 300–700 °C since the oxygen vacancy defects are suppressed, then it increases at 800 °C possibly due to the out-diffusion of oxygen atoms from the film. Meanwhile, the carrier mobility increases with temperature due to higher crystallinity and larger crystallite size. The film resistivity increases at 300–700 °C then decreases at 800 °C, which should be ascribed primarily to the variation of carrier concentration.

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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.

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Effect of Annealing Temperature on the Optical and Structural Properties of Ge Doped ZnO Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.304.79 ◽

2011 ◽

Vol 304 ◽

pp. 79-83

Author(s):

Dong Hua Fan ◽

Kai Zhen Huang ◽

Yu Bao Huang

Keyword(s):

Structural Properties ◽

Photoelectron Spectroscopy ◽

Annealing Temperature ◽

Free Exciton ◽

Ultra Violet ◽

Zno Films ◽

Violet Emission ◽

X Ray ◽

High Annealing ◽

Doped Zno

Ge doped ZnO films were synthesized on silicon substrate via RF magnetron co-sputtering methods. The effects of annealing temperature on the optical and structural properties of the Ge doped ZnO films were investigated by means of photoluminescence spectra, X-ray diffraction, and X-ray Photoelectron Spectroscopy. The ultra-violet emission should be related with the free-exciton recombination, and blue and yellow emissions should be attributed to the defect state caused by Ge. The varieties of annealing temperature affect greatly the optical properties. The high annealing temperature leads to the oxidation of Ge and the formation of Zn2GeO4, which could lead to the change of PL spectra.

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Compositional, Structural, Morphological, and Optical Properties of ZnO Thin Films Prepared by PECVD Technique

Coatings ◽

10.3390/coatings11020202 ◽

2021 ◽

Vol 11 (2) ◽

pp. 202

Author(s):

Noureddine Hacini ◽

Mostefa Ghamnia ◽

Mohamed Amine Dahamni ◽

Abdelwaheb Boukhachem ◽

Jean-Jacques Pireaux ◽

...

Keyword(s):

Thin Films ◽

Optical Properties ◽

Substrate Temperature ◽

Photoelectron Spectroscopy ◽

Morphological Properties ◽

Zno Thin Films ◽

Zno Films ◽

Textured Surfaces ◽

Xps Spectra ◽

X Ray

ZnO thin films were synthesized on silicon and glass substrates using the plasma-enhanced chemical vapor deposition (PECVD) technique. Three samples were prepared at substrates temperatures of 200, 300, and 400 °C. The surface chemical composition was analyzed by the use of X-Ray Photoelectron spectroscopy (XPS). Structural and morphological properties were studied by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Optical properties were carried out by UV-visible spectroscopy. XPS spectra showed typical peaks of Zn(2p3/2), Zn(2p1/2), and O(1s) of ZnO with a slight shift attributed to the substrate temperature. XRD analysis revealed hexagonal wurtzite phases with a preferred (002) growth orientation that improved with temperature. Calculation of grain size and dislocation density revealed the crystallization improvement of ZnO when the substrate temperature varied from 200 to 400 °C. SEM images of ZnO films showed textured surfaces composed of grains of spherical shape uniformly distributed. The transmittance yields are reaching 80%, and the values of the band-gap energy indicate that the ZnO films prepared by PECVD present transparent and semiconducting properties.

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Electrodeposition of Porous ZnO Electrodes in the Presence of Cetyltrimethylammonium Bromide

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.105-106.639 ◽

2010 ◽

Vol 105-106 ◽

pp. 639-642

Author(s):

Li Rong Yang ◽

Wen Li Zhang ◽

Man Zhen Duan ◽

Zheng Guo Jin

Keyword(s):

Photoelectron Spectroscopy ◽

Optical Transmittance ◽

Zno Films ◽

Ammonium Bromide ◽

Xps Spectra ◽

X Ray ◽

Cathodic Electrodeposition ◽

Sem Image ◽

New Strategy

A new strategy involving the introduction of the common cationic surfactant cetyltrimethyl ammonium bromide (CTAB) for the cathodic electrodeposition of ZnO electrodes from Zn(NO3) solutions by cyclic voltammetry has been developed. Frizzily lamellar and porous ZnO films were obtained. The deposited films were characterized by X-ray diffraction (XRD) in the range of low-angle and wide-angle, X-ray photoelectron Spectroscopy (XPS), scanning electron microscopy (SEM), and UV-Vis transmittance spectroscopy. The role of the CTAB was also discussed. Under the optimal contents of CTAB, the XRD pattern shows that the as-synthesized ZnO is lamellar nanostructure and SEM image demonstrates that porous and frizzyly lamellar ZnO crystals are formed; XPS spectra of as-deposited film shows that the electrodeposition mainly consists of Zn and O and the Optical transmittance spectra of ZnO film indicates that optical transmittance is low and gradually decreases with the wavelength lessening in the visible light region. Mechanisms are proposed for the electrochemical deposition and the beneficial role of CTAB.

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Effects of the carrier concentration on polarity determination in Ga-doped ZnO films by hard x-ray photoelectron spectroscopy

Applied Surface Science ◽

10.1016/j.apsusc.2017.10.157 ◽

2018 ◽

Vol 433 ◽

pp. 1148-1153 ◽

Cited By ~ 7

Author(s):

Huaping Song ◽

Hisao Makino ◽

Masaaki Kobata ◽

Junichi Nomoto ◽

Keisuke Kobayashi ◽

...

Keyword(s):

Carrier Concentration ◽

Photoelectron Spectroscopy ◽

Zno Films ◽

X Ray ◽

Polarity Determination ◽

Doped Zno

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Investigation of Oxygen Vacancy and Interstitial Oxygen Defects in ZnO Films by Photoluminescence and X-Ray Photoelectron Spectroscopy

Chinese Physics Letters ◽

10.1088/0256-307x/24/7/089 ◽

2007 ◽

Vol 24 (7) ◽

pp. 2108-2111 ◽

Cited By ~ 123

Author(s):

Fan Hai-Bo ◽

Yang Shao-Yan ◽

Zhang Pan-Feng ◽

Wei Hong-Yuan ◽

Liu Xiang-Lin ◽

...

Keyword(s):

Oxygen Vacancy ◽

Photoelectron Spectroscopy ◽

Zno Films ◽

Interstitial Oxygen ◽

X Ray ◽

Oxygen Defects

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Optical, XPS and XRD Studies of Semiconducting Copper Sulfide Layers on a Polyamide Film

International Journal of Photoenergy ◽

10.1155/2009/304308 ◽

2009 ◽

Vol 2009 ◽

pp. 1-8 ◽

Cited By ~ 69

Author(s):

Valentina Krylova ◽

Mindaugas Andrulevičius

Keyword(s):

Photoelectron Spectroscopy ◽

Copper Sulfide ◽

Diffusion Method ◽

X Ray Diffraction ◽

Xps Spectra ◽

X Ray ◽

Xrd Studies ◽

Polyamide Film ◽

Indirect Band Gap ◽

Xrd Method

Copper sulfide layers were formed on polyamide PA 6 surface using the sorption-diffusion method. Polymer samples were immersed for 4 and 5 h in 0.15 mol⋅ solutions and acidified with HCl (0.1 mol⋅) at . After washing and drying, the samples were treated with Cu(I) salt solution. The samples were studied by UV/VIS, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) methods. All methods confirmed that on the surface of the polyamide film a layer of copper sulfide was formed. The copper sulfide layers are indirect band-gap semiconductors. The values of are 1.25 and 1.3 eV for 4 h and 5 h sulfured PA 6 respectively. Copper XPS spectra analyses showed Cu(I) bonds only in deeper layers of the formed film, while in sulfur XPS S 2p spectra dominating sulfide bonds were found after cleaning the surface with ions. It has been established by the XRD method that, beside , the layer contains as well. For PA 6 initially sulfured 4 h, grain size forchalcocite, , was nm and fordjurleite, , it was 54.17 nm. The sheet resistance of the obtained layer varies from 6300 to 102 .

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Effects of Thermal Annealing on the Properties of Zirconium-Doped MgxZn1−XO Films Obtained through Radio-Frequency Magnetron Sputtering

Membranes ◽

10.3390/membranes11050373 ◽

2021 ◽

Vol 11 (5) ◽

pp. 373

Author(s):

Wen-Yen Lin ◽

Feng-Tsun Chien ◽

Hsien-Chin Chiu ◽

Jinn-Kong Sheu ◽

Kuang-Po Hsueh

Keyword(s):

Magnetron Sputtering ◽

Radio Frequency ◽

Photoelectron Spectroscopy ◽

Annealing Temperature ◽

Radio Frequency Magnetron ◽

Radio Frequency Magnetron Sputtering ◽

X Ray Diffraction ◽

Free Electrons ◽

X Ray ◽

Mg Content

Zirconium-doped MgxZn1−xO (Zr-doped MZO) mixed-oxide films were investigated, and the temperature sensitivity of their electric and optical properties was characterized. Zr-doped MZO films were deposited through radio-frequency magnetron sputtering using a 4-inch ZnO/MgO/ZrO2 (75/20/5 wt%) target. Hall measurement, X-ray diffraction (XRD), transmittance, and X-ray photoelectron spectroscopy (XPS) data were obtained. The lowest sheet resistance, highest mobility, and highest concentration were 1.30 × 103 Ω/sq, 4.46 cm2/Vs, and 7.28 × 1019 cm−3, respectively. The XRD spectra of the as-grown and annealed Zr-doped MZO films contained MgxZn1−xO(002) and ZrO2(200) coupled with Mg(OH)2(101) at 34.49°, 34.88°, and 38.017°, respectively. The intensity of the XRD peak near 34.88° decreased with temperature because the films that segregated Zr4+ from ZrO2(200) increased. The absorption edges of the films were at approximately 348 nm under 80% transmittance because of the Mg content. XPS revealed that the amount of Zr4+ increased with the annealing temperature. Zr is a potentially promising double donor, providing up to two extra free electrons per ion when used in place of Zn2+.

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