Development of ZnO/Ta2O5 heterojunction using low-temperature technological processes

2011 ◽  
Vol 1287 ◽  
Author(s):  
R. Baca ◽  
J. A. Andraca ◽  
M. G. Arellano ◽  
G. R. Paredes ◽  
R. P. Sierra
Keyword(s):  
Low Temperature ◽  
Transient Response ◽  
Rectangular Pulse ◽  
Voltage Source ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Air Atmosphere ◽  
Current Voltage ◽  
Potential Alternative

ABSTRACTZnO/Ta2O5 heterojunctions were formed on glass substrates using low temperature processes. Formerly insulating Ta2O5 films were deposited on glass substrates by vacuum evaporation using Ta2O5 powder, Afterwards transparent and conductive ZnO films were formed on the Ta2O5 films by thermal oxidation at 3200C in air atmosphere of zinc (Zn) films deposited by dc sputtering process. Structural and optical properties of ZnO were investigated by X-ray diffraction (XRD) and photoluminescence (PL). The Ta2O5 insulating films were characterized by Raman scattering. The ZnO/Ta2O5 heterojunction was characterized by current-voltage measurements at room temperature as well as transient response under a rectangular-pulse voltage source. The electrical and the transient response suggest that the ZnO/Ta2O5 heterojunction is a potential alternative for the fabrication of alternating-current-driven thin film electroluminescent (ACTFEL) devices.

Optically Transparent of N-ZnO/p-NiO Heterojunction for Ultraviolet Photodetector Application

2011 ◽  
Vol 687 ◽  
pp. 711-715 ◽  
Author(s):  
Shu Yi Tsai ◽  
Min Hsiung Hon ◽  
Yang Ming Lu
Keyword(s):  
Zno Films ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Voltage Curve ◽  
Current Voltage ◽  
Current Voltage Curve ◽  
Order Of Magnitude ◽  
Uv Visible ◽  
Diode Behavior ◽  
P Type

Transparent p–n heterojunction diodes consisting of n-type ZnO and p-type NiO thin films were prepared on glass substrates by r.f. magnetron sputtering. The structural and optical properties of the n-ZnO/p-NiO heterojunction were characterized by X-ray diffraction (XRD), UV–visible spectroscopy, Hall measurement, and I-V photocurrent measurements. The XRD shows that ZnO films are highly crystalline in nature with preferred orientation along the (0 0 2) orientation. The optical transmittances of ZnO and NiO films are 87% and 80%, respectively. The current–voltage curve of the heterojunction demonstrates obvious rectifying diode behavior in a dark environment. The lowest of leakage current is 7.73x10−8 A/cm2 for n-ZnO/p-NiO heterojunction diode. Upon UV irradiation, it was found that the detector current was increased by more than one order of magnitude. It was also found that the corresponding time constant for turn-on transient was τon = 27.9 ms while that for turn-off transient was τoff= 62.8 ms.

XRD Investigations on Film Thickness and Substrate Temperature Effects of DC Magnetron Sputtered ZnO Films

2013 ◽  
Vol 845 ◽  
pp. 241-245
Author(s):  
Jian Wei Hoon ◽  
Kah Yoong Chan ◽  
Cheng Yang Low
Keyword(s):  
Film Thickness ◽  
Substrate Temperature ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Direct Current Plasma ◽  
Crystallite Sizes ◽  
Magnetron Sputter Deposition ◽  
Magnetron Sputter ◽  
Diffraction Patterns

In this paper, direct current plasma magnetron sputter deposition technique was employed to deposit zinc oxide (ZnO) films on glass substrates. The magnetron sputtering process parameters including film thickness and substrate temperature were investigated. The crystallite sizes of the ZnO films were extracted from the measured X-ray diffraction patterns. The correlation of the crystallite size of the ZnO films with the film thickness and the substrate temperature will be discussed in this paper.

scholarly journals INFLUENCE OF ELECTRIC FIELD ON ADHESION AND STRUCTURE OF CONDUCTING FILMS ON DIELECTRIC SUBSTANCES

2017 ◽  
Vol 60 (8) ◽  
pp. 100 ◽  
Author(s):  
Nikolai S. Pshchelko ◽  
Ekaterina G. Vodkailo ◽  
Vladimir V. Tomaev ◽  
Boris D. Klimenkov ◽  
Veniamin L. Koshevoi ◽  
...  
Keyword(s):  
Electric Field ◽  
Dielectric Substrate ◽  
Zno Films ◽  
Electric Voltage ◽  
X Ray ◽  
Dry Air ◽  
Glass Substrates ◽  
Plasma Sputtering ◽  
Air Atmosphere ◽  
Extended Surface

Some results are provided confirming that modifying of the zinc films fabricated on glass substrates by a resulting effect of heat treatment in an atmosphere of dry air and action of cross electric field is possible. Using scanning electron microscopy (measured with the Zeiss Merlin microscope) the surface morphology of the films was studied. Also, the elemental composition of the films by micro-X-ray spectral analysis was studied. On the glass substrates, by the method of vacuum thermal evaporation, zinc films (Zn) with thickness of ~ 500 nm were obtained. In order to form ZnO films, the original films were treated at 250 °C in a dry air atmosphere, and in another case - in addition to the sample a transverse electric field with a potential of 300 V was applied. Platinum films on the silicon dioxide layer were obtained using the method of the ion-plasma sputtering. These layers were investigated by X-ray phase analysis, electron and atomic force microscopy. The thickness of platinum layers was 50 and 100 nm. During the deposition (deposition temperature – 300 °C, deposition rate - 5 nm / min), applied voltage between the platinum film and the silicon plate was 5 V. The films, obtained by applying a biasing, showed a more homogeneous fine-grained structure and a higher rate of growth than the original samples.  In this way ZnO films can be manufactured with the extended surface. The possibility of significant changes caused by electric field use in adhesion, structure and conductive properties of the coatings is discussed. The method of depositing platinum on a dielectric substrate with an additional electrostatic field is also substantiated. It is shown that the application of an electric voltage to the film leads to a significant change in the structure of the resulting coating.Forcitation:Pshchelko N.S., Vodkailo E.G., Tomaev V.V., Klimenkov B.D., Koshevoi V.L., Belorus A.O. Influence of electric field on adhesion and structure of conducting films on dielectric substances. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 8. P. 100-104.

Resistive Switching Behaviour of Dip Coated ZnO Films with the Changing with Drawal Speed

2020 ◽  
Vol 978 ◽  
pp. 384-389
Author(s):  
Sritama Roy ◽  
Saswati Soumya Dash ◽  
Prasanna Kumar Sahu ◽  
Smita Mishra ◽  
Jyoti Prakash Kar
Keyword(s):  
Thin Films ◽  
Resistive Switching ◽  
Sol Gel ◽  
Dip Coating ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Thin Film Thickness ◽  
Withdrawal Speed ◽  
Current Voltage ◽  
P Type

Zinc Oxide (ZnO) thin films were produced by the sol gel dip coating process on the p-type silicon substrate with various withdrawal speeds changing from 1 to 4 cm/min, respectively. The films were annealed at a temperature of 500 °C for an hour in air ambient. The thin film thickness was found to be raised with the rise in withdrawal speed. The uniform distribution of the grains was appeared for all the films. The evolution of c-axis oriented (002) peak was revealed from X-ray diffraction (XRD) studies. The microstructural and optical properties of ZnO films were investigated by Raman, FTIR and photoluminescence spectroscopy (PL). The resistive switching properties of ZnO based memristors were studied by performing the current-voltage (I-V) measurements, where the thin films coated with lower withdrawal speed, have shown better switching property with rapid rise and fall of current during SET and RESET process, respectively.

Effect of Solution Concentration in the Optical and Structural Properties of ZnO Thin Films

2018 ◽  
Vol 18 ◽  
pp. 113-117 ◽  
Author(s):  
Abdelkader Hafdallah ◽  
Aimane Guedri ◽  
Mohamed Salah Aida ◽  
Nadhir Attaf
Keyword(s):  
Thin Films ◽  
Solution Concentration ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Glass Substrates ◽  
Optical Band Gaps ◽  
Optical Films ◽  
Spray Technique ◽  
Uv Visible

In the present work we prepared conducting and transparent thin films ZnO with different solution concentrations by pyrolysis spray technique on glass substrates. These films are obtained starting from solution of zinc acetate dehydrate [Zn(CH3COO)2.2H2O] dissolved in methanol, at substrate temperature fixed T =350°C with a concentration of solution vary from 0.05-0.2 M. Our interest is on the investigation of solution concentration on the structural and optical properties of these films. The X-ray diffraction (XRD) results showed that the synthesized ZnO films are polycrystalline with preferred orientation along the (002) plane. The optical films characterization was carried out by the UV-Visible transmission. The optical gap and films disorder were deduced from the absorption spectra, The values of optical band gaps vary between 3.24 and 3.43 eV.

Thin Films: Growth of Transparent and Conductive Polycrystalline (0001)-ZnO Films on Glass Substrates Under Low-Temperature Hydrothermal Conditions (Adv. Funct. Mater. 15/2012)

2012 ◽  
Vol 22 (15) ◽  
pp. 3098-3098 ◽  
Author(s):  
Matejka Podlogar ◽  
Jacob J. Richardson ◽  
Damjan Vengust ◽  
Nina Daneu ◽  
Zoran Samardžija ◽  
...  
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Zno Films ◽  
Hydrothermal Conditions ◽  
Glass Substrates

OPTICAL CHARACTERIZATION OF ZnO NANOROD ARRAYS GROWN FROM SOLUTION

2010 ◽  
Vol 09 (05) ◽  
pp. 447-451 ◽  
Author(s):  
WALTER WATER ◽  
TE-HUA FANG ◽  
LIANG-WEN JI ◽  
CHING-CHIN LEE
Keyword(s):  
Zno Nanorods ◽  
Zinc Nitrate ◽  
Nitrate Hexahydrate ◽  
Zno Nanorod ◽  
Nanorod Arrays ◽  
Zno Nanorod Arrays ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Current Voltage ◽  
Ito Glass

ZnO nanorods were synthesized on ZnO / ITO glass substrates using an aqueous solution of zinc nitrate hexahydrate and hexamethylenetetramine. The effects of hexamethylenetetramine concentration on the crystalline structure and surface morphology of ZnO nanorods were investigated. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to analyze the crystalline characteristics and microstructures of the nanorod arrays. Ultraviolet/visible spectroscopy and photoluminescence (PL) spectra were used to characterize the optical properties of ZnO nanorods. Larger and brighter photoluminescent ZnO nanorods were obtained from solutions with higher hexamethylenetetramine concentrations. A nanogenerator based on ZnO nanorod arrays was fabricated in the investigation. The nanogenerator's current–voltage characteristics with Schottky-like behavior were discussed.

Preparation at Low-Temperature and Characterization of TiO2 Film Used for Solar Cells

2013 ◽  
Vol 537 ◽  
pp. 205-208
Author(s):  
Xiao Qiang Wang ◽  
Yue Liu Li ◽  
Jian Min Wang ◽  
Jing Guo ◽  
Ming Ya Li
Keyword(s):  
Low Temperature ◽  
Fill Factor ◽  
Sol Gel ◽  
Influence Factors ◽  
Raw Material ◽  
Tetrabutyl Titanate ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Photoelectric Properties

In this work, nanocrystalline TiO2 powder was prepared by the sol-gel method via tetrabutyl titanate as raw material, non-ion surfactant TO8 as a template. Then the nanocrystalline TiO2 thin film electrodes which were coated on FTO glass substrates via the slurry consiting of TiO2 powder prepared by us and the trabutyl titanate precursor were successfully prepared by using a simple and convenient hydrothermal method at low temperature. The structure and morphology of powders and films were characterized by X-ray diffraction, scanning electric microscopy. The influence factors on the samples were discussed. The photoelectric properties of cells assembled by the films were measured. The results show that, at 25°C and under 1000W/m2 light intensity，open voltage is 708mV, Jsc is 14.648mA/cm2, fill factor is 53.788, the conversion efficiency is 5.5988%.

Effects of Annealing on Properties of (Na,Mg):ZnO Thin Films Deposited by Sol-Gel Method

2014 ◽  
Vol 898 ◽  
pp. 33-36 ◽  
Author(s):  
Cai Zhen Zhang ◽  
Yong Gang Chen ◽  
Su Liu
Keyword(s):  
Annealing Temperature ◽  
Sol Gel ◽  
Zno Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Coating Method ◽  
Method Effects ◽  
Structural Surface ◽  
Co Doped

Na/Mg co-doped (Na,Mg):ZnO films were fabricated on pyrex glass substrates by sol-gel spin-coating method. Effects of annealing on properties of the films were particularly investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmittance spectra. The internal stress of the films annealed at different temperature was calculated. Experimental and analytical results show that some NaCl freeze-out derivatives will appear on films when the annealing temperature is too low, with the increasing annealing temperature, the c-axis tensile stress is sharply decreased first, then the c-axis stress was changed into press stress and its value is increased continuously, so the structural, surface and the optical properties of the films improve first and deteriorate afterwards.

UV photoconductors based on Ga-doped ZnO films

2005 ◽  
Vol 891 ◽  
Author(s):  
Leelaprasanna J. Mandalapu ◽  
Faxian Xiu ◽  
Zheng Yang ◽  
Jianlin Liu
Keyword(s):  
Uv Light ◽  
Zno Films ◽  
Metal Contacts ◽  
X Ray Diffraction ◽  
Detection Capability ◽  
Current Voltage ◽  
Structural And Electrical Properties ◽  
Voltage Dependent ◽  
20 Nm ◽  
Secondary Ion

ABSTRACTGa-doped n-type ZnO films were grown by molecular-beam epitaxy (MBE) on R-plane sapphire substrates. Material characterizations such as photoluminescence (PL), X-ray diffraction (XRD), secondary ion mass spectroscopy (SIMS) and Hall measurements were carried out to characterize the optical, structural, and electrical properties of the film. Photoconductor devices for ultraviolet (UV) light detection were fabricated by depositing Al (250 nm)/Ti (20 nm) ohmic metal contacts. Linear characteristics were obtained from current-voltage (I-V) measurements that showed response to UV and visible illumination. Voltage dependent photocurrent (PC) spectra and responsivity spectrum were obtained to characterize the detection capability of the device in the UV region.

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