Change in polarity of zinc oxide films grown on sapphire substrates without insertion of any buffer layer

2008 ◽  
Vol 23 (12) ◽  
pp. 3269-3272 ◽  
Author(s):  
Yutaka Adachi ◽  
Naoki Ohashi ◽  
Tsuyoshi Ohnishi ◽  
Takeshi Ohgaki ◽  
Isao Sakaguchi ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Zno Films ◽  
Ion Scattering ◽  
Ceramic Target ◽  
Interfacial Phase ◽  
Sapphire Substrates ◽  
Zinc Oxide Films ◽  
Ion Scattering Spectroscopy ◽  
Doped Zno ◽  
Polarity Change

We have investigated the polarity of zinc oxide (ZnO) and Al-doped ZnO films grown on (11¯20) and (0001) sapphire substrates, using coaxial impact collision ion scattering spectroscopy. The films grown by pulsed laser deposition with a nominally undoped ZnO ceramic target had a (000¯1) surface, whereas the films prepared with a 1 mol% Al-doped ZnO ceramic target had a (0001) surface. The usage of Al-doped and undoped targets caused no difference in the in-plane lattice orientation. Electron microscope observations revealed that polarity change due to doping occurred without the formation of any interfacial phase between ZnO and sapphire.

scholarly journals SYNTHESIS AND OPTICAL PROPERTIES OF Ni-DOPED ZnO GROWN BY ELECTROCHEMICAL DEPOSITION

Doklady BGUIR ◽  
2020 ◽  
Vol 18 (2) ◽  
pp. 37-44
Author(s):  
K. O. Yanushkevich ◽  
E. B. Chubenko ◽  
V. P. Bondarenko
Keyword(s):  
Zinc Oxide ◽  
Raman Scattering ◽  
Electrochemical Deposition ◽  
Current Density ◽  
Oxide Films ◽  
Measuring System ◽  
Zno Films ◽  
Photoluminescence Spectra ◽  
Zinc Oxide Films ◽  
Doped Zno

This paper is targeted at studying the patterns of deposition by electrochemical method of Ni-doped ZnO films, including registering and analyzing their photoluminescence and Raman scattering spectra. We have studied the electrochemical deposition of nickel-doped zinc oxide films on single-crystal silicon substrates from aqueous solutions of zinc and nickel nitrates. The deposition was conducted from aqua solutions of Zn and Ni nitrates in a standard double-electrode electrochemical cell in galvanostatic mode with the current density from 5 to 20 mA/cm2 and deposition time from 5 to 30 min. The Raman scattering on nickel-doped zinc oxide films was examined via laser Raman spectrometer SOL Instruments Confotec NR500. The analysis of Raman spectra showed that an increase of cathodic current density deposition leads to an enhanced concentration of a doping agent in the films. Photoluminescence spectra of the samples were registered on a laser spectral measuring system based on monochromator-spectrograph SOLAR TII MS 7504i where a monochromatic line with the 345-nm wavelength, which was extracted from the spectrum of Xe-lamp by means of double monochromator Solar TII DM160, was used as the excitation source. The research demonstrates that the emmission intensity increases with the thickness of the deposited film, and the position of maximums of the radiation line remains unchanged in a visible wavelength range and on photoluminescence spectra with fixed current density. The change in the density of the cathode current leads to a shift in the position of the photoluminescence spectra maximum, which indicates restructuring of defects and dopant atoms in the doped semiconductor, which in turn changes the position of the corresponding levels in the band gap of the material.

Analysis of Sputtered Zinc Oxide Films

1980 ◽  
Vol 38 ◽  
pp. 416-417
Author(s):  
T. A. Emma ◽  
M. P. Singh
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Piezoelectric Materials ◽  
Oxide Films ◽  
Optical Quality ◽  
Zno Films ◽  
Rf Power ◽  
X Ray Diffraction ◽  
Sputtered Films ◽  
Zinc Oxide Films

Optical quality zinc oxide films have been characterized using reflection electron diffraction (RED), replication electron microscopy (REM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Significant microstructural differences were observed between rf sputtered films and planar magnetron rf sputtered films. Piezoelectric materials have been attractive for applications to integrated optics since they provide an active medium for signal processing. Among the desirable physical characteristics of sputtered ZnO films used for this and related applications are a highly preferred crystallographic texture and relatively smooth surfaces. It has been found that these characteristics are very sensitive to the type and condition of the substrate and to the several sputtering parameters: target, rf power, gas composition and substrate temperature.

Low Temperature Deposition of Zinc Oxide Films

2003 ◽  
Vol 763 ◽  
Author(s):  
H. W. Lee ◽  
Y. G. Wang ◽  
S. P. Lau ◽  
B. K. Tay
Keyword(s):  
Zinc Oxide ◽  
Carrier Concentration ◽  
Vacuum Arc ◽  
Zno Films ◽  
Al Alloy ◽  
Pure Zinc ◽  
Zinc Oxide Films ◽  
Alloy Target ◽  
Temperature Deposition ◽  
Filtered Cathodic Vacuum Arc

AbstractA detailed study of zinc oxide (ZnO) films prepared by filtered cathodic vacuum arc (FCVA) technique was carried out. To deposit the films, a pure zinc target was used and O2 was fed into the chamber. The electrical properties of both undoped and Al-doped ZnO films were studied. For preparing the Al-doped films, a Zn-Al alloy target with 5 wt % Al was used. The resistivity, Hall mobility and carrier concentration of the samples were measured. The lowest resistivity that can be achieved with undoped ZnO films was 3.4×10-3 Ωcm, and that for Al-doped films was 8×10-4 Ωcm. The carrier concentration was found to increase with Al doping.

Characteristics of Zinc Oxide Film Prepared by Chemical Bath Deposition Method

2014 ◽  
Vol 602-603 ◽  
pp. 871-875
Author(s):  
Yen Pei Fu ◽  
Jian Jhih Chen
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Chemical Bath Deposition ◽  
Deposition Time ◽  
Oxide Films ◽  
Hexagonal Structure ◽  
Zno Films ◽  
Zinc Oxide Film ◽  
Incident Wavelength ◽  
Zinc Oxide Films

In this study, ZnO films, prepared by Chemical Bath Deposition (CBD), are applied as the conductive layers for thin film solar cells. Zinc acetate is used as a source of zinc, and different proportions of ammonia solution are added and well mixed. The growth of zinc oxide films in reaction solutions is taken place at 80°C and then heated to 500°C for one hour. In this study, the different ammonia concentrations and deposition times is controlled. The thin film structure is Hexagonal structure, which is determined by X-ray diffraction spectrometer (XRD) analysis. Scanning electron microscopy (SEM) is used as the observation of surface morphology, the bottom of the film is the interface where the heterogeneous nucleation happens. With the increase of deposition time, there were a few attached zinc oxide particles, which is formed by homogeneous nucleation. According to UV / visible light (UV / Vis) absorption spectrometer transmittance measurements and the relationship between/among the incident wavelength, it can be converted to the energy gaps (Eg), which are about 3.0 to 3.2eV, by using fluorescence spectroscopy analysis. The emission of zinc oxide films has two wavelengths which are located on 510nm and 570nm. According to Based on the all analytic results, the ammonia concentration at 0.05M, and the deposition time is 120 minutes, would obtain the conditions of ZnO films which is more suitable for applications of conductive layer material in thin film solar cell.

scholarly journals Characterization and thermoluminescence study of gamma irradiated Tb-doped ZnO and undoped ZnO synthesized by spray pyrolysis method

Nova Scientia ◽  
2021 ◽  
Vol 13 (27) ◽  
Author(s):  
Alejandro Ortiz-Morales ◽  
Manuel García-Hipólito ◽  
Epifanio Cruz-Zaragoza ◽  
Ramón Gómez-Aguilar
Keyword(s):  
Zinc Oxide ◽  
Gamma Radiation ◽  
Spray Pyrolysis ◽  
Oxide Films ◽  
Spray Pyrolysis Method ◽  
Order Kinetic ◽  
Zinc Oxide Films ◽  
Pyrolysis Method ◽  
Wide Range ◽  
Doped Zno

High gamma dose-resistant undoped ZnO and Tb-doped ZnO thermoluminescent (TL) micro-phosphors were prepared by the spray pyrolysis method. Scanning electron microscopy shows crystalline rods with hexagonal morphology, (0.1-0.4 µm diameter, and about 1 µm length). Raman spectra dispersion reveals a würtzite form. Photoluminescence (PL) study of irradiated zinc oxide films indicates the generation of defects produced by gamma irradiation resulting in an increased probability of electron-hole exciton recombination. PL spectrum shows emission bands from 5D4-7Fj=6,5,4,3 transitions ascribed to Tb3+ dopant in zinc oxide phosphor. X-ray diffraction patterns for both types of films growth (undoped ZnO and Tb-doped ZnO) are typical of zinc oxide crystalline structure, with no noticeable effect of Tb ions. Dosimetric properties, for both samples, show a low TL fading signal and TL reproducibility signal for undoped ZnO and Tb-doped ZnO samples was 29 and 57 %, respectively. The kinetic parameters such as activation energy E, frequency factor s, and Rm values, were obtained by Computerized Glow Curve Deconvolution (CGCD) assuming Mixed Order Kinetic model (MOK). The results show that the MOK well described the glow curves of zinc oxide films. The heating rate effects produced a broadening of glow peak located at 420 K. For purposes like radiation detector, atomic effective number (Zeff) was obtained: 27.74 and 56.47 for undoped ZnO and Tb-doped ZnO samples, respectively. The samples were exposed to gamma radiation in a wide range of 0.25–20 kGy dose. TL properties of undoped ZnO and Tb-doped ZnO samples show that these materials could be used to detect high doses in a gamma radiation field.

scholarly journals Electrical and Photoluminescence Properties of Mo-doped ZnO Films Deposited by Spray Pyrolysis

2018 ◽  
Vol 15 (3) ◽  
pp. 218-223 ◽  
Author(s):  
T. Sreenivasulu Reddy ◽  
G. Phaneendra Reddy ◽  
K.T. Ramakrishna Reddy
Keyword(s):  
Zinc Oxide ◽  
Spray Pyrolysis ◽  
Doping Concentration ◽  
Zno Films ◽  
Vibrational Modes ◽  
Photoluminescence Properties ◽  
Glass Substrates ◽  
Doped Zno ◽  
Electrical Analysis ◽  
Substrate Temperatures

Spray deposited Mo-doped zinc oxide (MZO) films were grown on glass substrates at different substrate temperatures (Ts)that varied in the range of 300°C-450 °C at aconstant Mo-doping concentration of 2 at. %.XRD spectra revealed better crystallinity of films prepared atTs400 °C. FTIR spectra showed the vibrational modes related toZn–O bonding.Photoluminescence spectra of MZO films showed a peakrelated toviolet emissionsbetween 400 nm and 420 nm. Electrical analysis showed n type semiconducting nature of the films and the films grown at Ts= 400 °C hadlow resistivity and high mobility.Adetailed analysis on theeffect of substrate temperatureon photoluminescence and electrical propertiesof MZO films wasdiscussed and reported.

scholarly journals Single step route to highly transparent, conductive and hazy aluminium doped zinc oxide films

RSC Advances ◽  
2018 ◽  
Vol 8 (74) ◽  
pp. 42300-42307 ◽  
Author(s):  
Jianwei Li ◽  
Sanjayan Sathasivam ◽  
Alaric Taylor ◽  
Claire J. Carmalt ◽  
Ivan P. Parkin
Keyword(s):  
Zinc Oxide ◽  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Oxide Films ◽  
Chemical Vapour ◽  
Single Step ◽  
Zinc Oxide Films ◽  
Doped Zno

A single step chemical vapour deposition route to highly conductive, transparent and hazy Al doped ZnO.

Characterization of Pulsed Laser Deposited Zinc Oxide

1992 ◽  
Vol 276 ◽  
Author(s):  
N. J. Ianno ◽  
L. McConville ◽  
N. Shaikh
Keyword(s):  
Zinc Oxide ◽  
Pulsed Laser ◽  
Laser Wavelength ◽  
Piezoelectric Response ◽  
Zno Films ◽  
Zinc Oxide Films ◽  
Substrate Temperatures ◽  
532 Nm ◽  
Deposited Films

ABSTRACTThe pulsed laser deposition of zinc oxide films (ZnO) has been studied as a function of laser wavelength, and substrate temperature. The deposited films were characterized by x-ray diffractometry, Auger electron spectroscopy, and scanning electron microscopy. Highly textured (002) ZnO films have been deposited at substrate temperatures of 300 C with laser wavelengths of 532 nm and 248 nm. However, the energy fluence of 248 nm radiation controls the degree of texturing, allowing highly textured films to be deposited at room temperature.Smart structures based on embedded, textured ZnO coated fibers, and wires exhibit excellent piezoelectric response to external stress.

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