X-RAY PHOTOELECTRON SPECTROSCOPIC STUDY ON               HIGH-ELECTRON-MOBILITY GALLIUM AND HYDROGEN CO-DOPED ZINC OXIDE THIN FILMS

In this study, gallium and hydrogen co-doped ZnO (HGZO) thin films were investigated. The films were deposited by sputtering from Ga-doped ZnO (GZO) ceramic target in hydrogen and argon plasma. The as-deposited HGZO films possess enhanced electron mobility of 48.6 cm2/Vs as compared to that of 39.4 cm2/Vs of GZO films, sputtered from the same target. Because of insignificant variation in crystallinity, this improvement is attributed to roles of hydrogen in crystalline lattice structure of the films. X-ray photoelectron spectroscopy (XPS) is employed as an essential technique for quantitative analyses and chemical binding states of films constituent elements. The roles of hydrogen are clarified through the binding states of Zn 2p, O 1s and Ga 3d. Obtained results suggest that the films are deposited more effectively in hydrogen plasma. Some point defects such as oxygen vacancies (VO), dangling bonds can be passivated in form of H+VOHO and O–H bonds. As a result, the reduction of scattering centers is indicated as a reason for the mobility improvement of the HGZO films.

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Resistive Switching Characteristics of Li-Doped ZnO Thin Films Based on Magnetron Sputtering

Materials ◽

10.3390/ma12081282 ◽

2019 ◽

Vol 12 (8) ◽

pp. 1282 ◽

Cited By ~ 8

Author(s):

Zhao ◽

Li ◽

Ai ◽

Wen

Keyword(s):

Thin Films ◽

Magnetron Sputtering ◽

Resistive Switching ◽

Photoelectron Spectroscopy ◽

Lattice Structure ◽

Zno Thin Films ◽

Bipolar Resistive Switching ◽

X Ray ◽

Doped Zno ◽

Switching Characteristics

A kind of devices Pt/Ag/ZnO:Li/Pt/Ti with high resistive switching behaviors were prepared on a SiO2/Si substrate by using magnetron sputtering method and mask technology, composed of a bottom electrode (BE) of Pt/Ti, a resistive switching layer of ZnO:Li thin film and a top electrode (TE) of Pt/Ag. To determine the crystal lattice structure and the Li-doped concentration in the resulted ZnO thin films, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) tests were carried out. Resistive switching behaviors of the devices with different thicknesses of Li-doped ZnO thin films were studied at different set and reset voltages based on analog and digital resistive switching characteristics. At room temperature, the fabricated devices represent stable bipolar resistive switching behaviors with a low set voltage, a high switching current ratio and a long retention up to 104 s. In addition, the device can sustain an excellent endurance more than 103 cycles at an applied pulse voltage. The mechanism on how the thicknesses of the Li-doped ZnO thin films affect the resistive switching behaviors was investigated by installing conduction mechanism models. This study provides a new strategy for fabricating the resistive random access memory (ReRAM) device used in practice.

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Electronic Structure of Co-doped ZnO Thin Films by X-ray Absorption and Emission Spectroscopy

Journal of the Korean Physical Society ◽

10.3938/jkps.55.167 ◽

2009 ◽

Vol 55 (1) ◽

pp. 167-172 ◽

Cited By ~ 12

Author(s):

S. Gautam ◽

P. Thakur ◽

K.H. Chae ◽

G.S. Chang ◽

M. Subramanain ◽

...

Keyword(s):

Thin Films ◽

Electronic Structure ◽

Emission Spectroscopy ◽

Zno Thin Films ◽

Absorption And Emission ◽

X Ray ◽

Doped Zno ◽

X Ray Absorption ◽

Absorption And Emission Spectroscopy ◽

Co Doped

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X-ray, reflection high electron energy diffraction and X-ray photoelectron spectroscopy studies of InSe and γ-In2Se3 thin films grown by molecular beam deposition

Thin Solid Films ◽

10.1016/0040-6090(94)90275-5 ◽

1994 ◽

Vol 237 (1-2) ◽

pp. 291-296 ◽

Cited By ~ 22

Author(s):

L. Brahim-Otsmane ◽

J.-Y. Emery ◽

M. Eddrief

Keyword(s):

Thin Films ◽

Electron Energy ◽

Photoelectron Spectroscopy ◽

Molecular Beam ◽

High Electron ◽

X Ray ◽

Molecular Beam Deposition ◽

Spectroscopy Studies ◽

Beam Deposition

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Preparation and Microstructure of acetate-based lead-free BSZT ferrolectric thin films using sol-gel technique

VNU Journal of Science Mathematics - Physics ◽

10.25073/2588-1124/vnumap.4316 ◽

2019 ◽

Vol 35 (1) ◽

Author(s):

Vu Thu Hien

Keyword(s):

Thin Films ◽

Conduction Mechanism ◽

Lattice Structure ◽

Sol Gel ◽

Lead Free ◽

Crystalline Lattice ◽

Plane Symmetry ◽

X Ray ◽

Gel Technique ◽

Current Behaviour

(Ba0.85Sr0.15)(Ti0.9Zr0.1)O3 (BSZT) lead-free ferroelectric thin films at the vicinity of the morphotropic phase boundary (MPB) were successfully deposited on Pt/Ti/SiO2/Si using a modified spin-coated sol-gel method. Microstructure and electrical properties of the thin film were studied. High resolution synchrotron X–ray powder diffraction (SXRD) combinied with Rietveld refinement revealed the samples crystalize in tetragonal perovskite structure with in-plane symmetry (c < a). Raman spectra also confirmed a tetragonal perovskite crystalline lattice structure. Polarisation studies demonstrate that BSZT films exhibit a rather high saturation polarisation of 22.25 µC cm−2. Leakage current behaviour was obtained and possible conduction mechanism is discussed.

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Influence of indium and hydrogen co-doping on optical and electrical properties of zinc oxide thin films deposited by DC magnetron sputtering

Science and Technology Development Journal ◽

10.32508/stdj.v22i2.1657 ◽

2019 ◽

Vol 22 (2) ◽

pp. 253-257

Author(s):

Nguyen Huu Truong ◽

Tinh Van Nguyen ◽

Tuan Anh Thanh Pham ◽

Dung Van Hoang ◽

Hung Minh Vu ◽

...

Keyword(s):

Thin Films ◽

Solar Cells ◽

Magnetron Sputtering ◽

Hydrogen Plasma ◽

Response Speed ◽

Indium Content ◽

Morphological Properties ◽

High Electron ◽

Dc Magnetron Sputtering ◽

Doped Zno

Introduction: ZnO-based thin films, known as potential transparent-conducting oxides (TCO), have still attracted much attention in applications for good-performance electrodes and inner layers in solar cells. Recently, the research tendency has focused on improving carrier mobility rather than carrier concentration to enhance performance and response speed of TCO thin films. In this work, Indium, and Hydrogen co-doped ZnO (HIZO) thin films were deposited by using DC magnetron sputtering technique in hydrogen-plasma atmosphere. Methods: Indium-doped ZnO ceramics were used as sputtering targets, in which, Indium content varied from 0.07 to 1.0 at.%. The electrical, optical, structural and surface morphological properties of the as-deposited films were investigated by using Hall effect-based measurement, UV-Vis spectra, X-ray diffraction (XRD) and fieldemission scanning electron microscopy (FE-SEM), respectively. Results: As a result, the HIZO films sputtered from the 0.1 at.% In-doped ZnO target and at H2/(H2+Ar) ratio of 3.5% exhibit high electron mobility (47 cm2/Vs), the lowest resistivity (4.9x10-4 Ω.cm) and sheet resistance (4.7 Ω/sq.), simultaneously, high average transmittance (>80%) in the visible – near IR spectrum regions. Conclusion: Based on these results, the HIZO films are considered as potential TCO thin films that can be well-used as transparent electrodes in solar cells.

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Physical Investigations of (Co, Mn) Co-Doped ZnO Nanocrystalline Films

Nanomaterials ◽

10.3390/nano10081507 ◽

2020 ◽

Vol 10 (8) ◽

pp. 1507

Author(s):

Bechir Yahmadi ◽

Olfa Kamoun ◽

Badriyah Alhalaili ◽

Safia Alleg ◽

Ruxandra Vidu ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Magnetic Measurements ◽

Texture Coefficient ◽

Room Temperature Ferromagnetism ◽

Band Gap Energy ◽

X Ray ◽

Co Doping ◽

Glass Substrates ◽

Doped Zno ◽

Co Doped

Undoped as well as (Co, Mn) co-doped Zinc oxides have been effectively developed on glass substrates, taking advantage of the spray pyrolysis procedure. The X-ray diffraction XRD as well as X-ray photoelectron spectroscopy (XPS) measurements have recognized a pure hexagonal wurtzite form of ZnO, and no other collateral phases such as MnO2 or CoO2 have been observed as a result of doping. The calculated values of the texture coefficient (TC) were between 0.15 and 5.14, indicating a dominant orientation along the (002) plane. The crystallite size (D) varies with the (Co, Mn) contents. The dislocation density (δ) as well as the residual microstrains increased after Co and Mn doping. Furthermore, the surface morphology of the films has been affected significantly by the Co and Mn incorporation, as shown by the scanning electron microscopy (SEM) investigation. The study of the optical properties exhibits a red shift of the band gap energy (Eg) with the (Co, Mn) co-doping. The magnetic measurements have shown that the undoped and (Co, Mn) co-doped ZnO thin films displayed room-temperature ferromagnetism (RTFM).

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