scholarly journals The effect of Sn-doping on optical, electrical and morphological properties of spray-pyrolysed ZnO films

2020 ◽  
Vol 10 (29) ◽  
pp. 1-12
Author(s):  
Andrey Escala Alves ◽  
Herval Ramos Paes Junior
Keyword(s):  
Spray Pyrolysis Technique ◽  
Optical Bandgap ◽  
Morphological Properties ◽  
Zno Films ◽  
Host Matrix ◽  
Sn Doping ◽  
Zinc Oxide Films ◽  
Morphological Aspects ◽  
Surface Electrical Conductivity ◽  
Top View

The present work has investigated the effects of tin doping on morphological and optical-electrical properties of zinc oxide films produced by spray-pyrolysis technique. The films exhibited droplet impact marks along the surface. Top-view micrographs disclosed black clusters of non-decomposed salts after tin doing. These morphological aspects have not compromised optical performance although they may have contributed to the rise in electrical resistivity due to charge scattering on the surface. Electrical conductivity was lowered as tin-doping concentration increased. Tin ions occupied interstitial sites in the host matrix and acted as conventional defects. The film transmittance at 550 nm was not significantly affected by tin doping, yet a slight loss in transparency was observed after 1 at. % Sn doping. Optical bandgap was reduced from 3.25 to 3.16 eV due to deep states when doping with 1 at. % Sn. The optical bandgap widened to 3.23 eV with incorporation of 2 at. % Sn. This behaviour is attributed to the Burstein-Moss effect.

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.

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.

ELECTRICAL AND OPTICAL PROPERTIES OF MULTILAYER SOL GEL ZnO COATINGS

2006 ◽  
Vol 20 (23) ◽  
pp. 3357-3364 ◽  
Author(s):  
TALAAT MOUSSA HAMMAD
Keyword(s):  
Carrier Mobility ◽  
Sol Gel ◽  
Dip Coating ◽  
Free Carrier ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Electrical And Optical Properties ◽  
Zinc Oxide Films ◽  
Free Carrier Density ◽  
Fine Microstructure

Multilayer transparent conducting zinc oxide films have been prepared on boro-silicate substrates by the commercially sol gel dip coating process. Each layer was fired at 550°C in a conventional furnace for 15 min. The final coatings were then tempered under a flux of forming gas ( N 2/ H 2) at 400°C for 2 h. The coatings were characterized by surface stylus profiling and optical spectroscopy (UV-NIR). Results show that (1) ZnO films with electrical resistivity of 6×10-4 Ω· cm , free carrier mobility of approximately 77 cm 2/ V · s and free carrier density of approximately 6.14×1019 cm -3 are obtained for multilayers 310 nm and (2) the transmittance is approximately 60.4% and the reflectance is nearly 34.7% are obtained at a wavelength of 800 nm when the thickness of the ZnO multilayers is 310 nm. The crystal structure and grain orientation of ZnO films were determined by X-ray diffraction. SEM investigations revealed that the surface morphology of growing ZnO films on boro-silicate substrate is dominated by the smooth surface with a fine microstructure.

scholarly journals Thermal engineering of stone increased prehistoric toolmaking skill

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Veronica Mraz ◽  
Mike Fisch ◽  
Metin I. Eren ◽  
C. Owen Lovejoy ◽  
Briggs Buchanan
Keyword(s):  
Heat Treatment ◽  
Human Agency ◽  
Heat Treating ◽  
Morphological Properties ◽  
Thermal Engineering ◽  
Morphological Aspects ◽  
Different Temperatures ◽  
Force Propagation

Abstract Intentional heat treating of toolstone has been documented to have begun at least by 70 K BP; however, the advantages of such treatment have been debated for decades. There are two schools of thought with regard to its purpose. One, is that it merely reduces the force required for flake propagation. A second is that it also alters flake morphological properties. We systematically tested these hypotheses by generating flakes from cores exposed to three different temperatures (ambient, 300 °C, and 350 °C) using automated propagation procedures that bypassed any human agency. While the force propagation magnitude is altered by heat treatment, the flakes were not. We examined these flakes according to nine measures of morphology. None differed significantly or systematically within the three categories. While our results confirm that heat treatment does reduce the force needed for flake propagation, they also demonstrate that such treatment has no significant effect on major morphological aspects of flake form.

scholarly journals Transparent ZnO Thin-Film Deposition by Spray Pyrolysis for High-Performance Metal-Oxide Field-Effect Transistors

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3423 ◽  
Author(s):  
Junhee Cho ◽  
Seongkwon Hwang ◽  
Doo-Hyun Ko ◽  
Seungjun Chung
Keyword(s):  
Thin Film ◽  
Metal Oxide ◽  
Spray Pyrolysis ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Spray Pyrolysis Technique ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Zno Films ◽  
Process Conditions

Solution-based metal oxide semiconductors (MOSs) have emerged, with their potential for low-cost and low-temperature processability preserving their intrinsic properties of high optical transparency and high carrier mobility. In particular, MOS field-effect transistors (FETs) using the spray pyrolysis technique have drawn huge attention with the electrical performances compatible with those of vacuum-based FETs. However, further intensive investigations are still desirable, associated with the processing optimization and operational instabilities when compared to other methodologies for depositing thin-film semiconductors. Here, we demonstrate high-performing transparent ZnO FETs using the spray pyrolysis technique, exhibiting a field-effect mobility of ~14.7 cm2 V−1 s−1, an on/off ratio of ~109, and an SS of ~0.49 V/decade. We examine the optical and electrical characteristics of the prepared ZnO films formed by spray pyrolysis via various analysis techniques. The influence of spray process conditions was also studied for realizing high quality ZnO films. Furthermore, we measure and analyze time dependence of the threshold voltage (Vth) shifts and their recovery behaviors under prolonged positive and negative gate bias, which were expected to be attributed to defect creation and charge trapping at or near the interface between channel and insulator, respectively.

Effect of Molarity of Precursor Solution on Nanocrystalline Zinc Oxide Thin Films

2009 ◽  
Vol 293 ◽  
pp. 99-105 ◽  
Author(s):  
Girjesh Singh ◽  
S.B. Shrivastava ◽  
Deepti Jain ◽  
Swati Pandya ◽  
V. Ganesan
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Solar Cells ◽  
Spray Pyrolysis ◽  
Spray Pyrolysis Technique ◽  
Precursor Solution ◽  
Zno Films ◽  
Scale Production ◽  
Transparent Conducting ◽  
Wide Range

During the last two decades, the use of transparent conducting films of non-stoichiometric and doped metallic oxides for the conversion of solar energy into electrical energy has assumed great significance. A variety of materials, using various deposition techniques, has been tried for this purpose [1-3]. Among these various materials, zinc oxide (ZnO) is one of the prominent oxide semiconductors suitable for photovoltaic applications because of its high electrical conductivity and optical transmittance in the visible region of the solar spectrum [4]. Furthermore, thin films of ZnO have shown good chemical stability against hydrogen plasma, which is of prime importance in a-Si:H-based solar-cell fabrication. Thus, zinc oxide can serve as a good candidate for replacing SnO2 and indium tin oxide (ITO) films in Si:H-based solar cells. One of the outstanding features of ZnO is its large excitonic binding energy, i.e. 60meV, leading to the existence of excitons at room temperature and even at higher temperatures [5-8]. These unique characteristics have generated a wide range of applications of ZnO. For example, gas sensors [9], surface acoustic devices [10], transparent electrodes and solar cells. Many techniques are used for preparing the transparent conducting ZnO films, such as RF sputtering [11], evaporation [12], chemical vapour deposition [13], ion beam sputtering [14] and spray pyrolysis [15–18]. Among these, the spray pyrolysis technique has attracted considerable attention due to its simplicity and large-scale production combined with low-cost fabrication. By using this technique, one can produce large-area coatings without any need for ultra-high vacuum. Thus, the capital cost and the production cost of high-quality zinc oxide semiconductor thin films are lowest among all other techniques. In the present work, we have synthesized ZnO films by using the spray pyrolysis technique. A number of films have been prepared by changing the molarity of the precursor solution. The prepared films have been characterized with regard to their structural, morphological and electrical properties.

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