Structure and Optical Properties of Mg0.5Zn0.5O Films

2011 ◽  
Vol 337 ◽  
pp. 383-386
Author(s):  
Quan Sheng Liu ◽  
Xi Yan Zhang ◽  
Xiao Chun Wang ◽  
Zhao Hui Bai ◽  
Neng Li Wang ◽  
...  
Keyword(s):  
Grain Size ◽  
Optical Properties ◽  
Quartz Glass ◽  
Absorption Edge ◽  
Sol Gel ◽  
Sem Image ◽  
Glass Substrates ◽  
Average Grain Size ◽  
Solar Blind ◽  
Cubic Structure

Mg0.5Zn0.5O films were prepared on quartz glass substrates by sol-gel method. Structure and optical properties of Mg0.5Zn0.5O film were studied.Results indicated that Mg0.5Zn0.5O film deposited on quartz glass is composed of two structures of ZnO hexagonal and MgO cubic. SEM image revealed that the film was homogenous and the average grain size of crystal was 40nm.Absorption spectrum indicated the absorption edge of hexagonal and cubic structures located in 332nm and 271nm respectively.The absorption edge of cubic structure locates in the solar blind region.The luminescence spectrum of sample is composed of three peaks at 383.7nm(3.23eV)，442.9nm(2.80eV) and 533.9nm(2.32eV) respectively.The peak of excitation spectrum is at 379nm(3.28eV).

Properties of Hexagonal Wurtzite Mg0.33Zn0.67O Films on Quartz Glass Substrates

2011 ◽  
Vol 337 ◽  
pp. 612-615
Author(s):  
Quan Sheng Liu ◽  
Xi Yan Zhang ◽  
Xiao Chun Wang ◽  
Zhao Hui Bai ◽  
Neng Li Wang ◽  
...  
Keyword(s):  
Grain Size ◽  
Absorption Spectrum ◽  
Quartz Glass ◽  
Sol Gel ◽  
Hexagonal Wurtzite Structure ◽  
Xrd Analysis ◽  
Excitation Peak ◽  
Lattice Constants ◽  
Glass Substrates ◽  
Average Grain Size

Mg0.33Zn0.67Ofilms were prepared on quartz glass substrates by Sol-Gel method. Structures and optical properties of Mg0.33Zn0.67Ofilms were studied. The results of XRD analysis indicates that the Mg0.33Zn0.67Ofilm is hexagonal wurtzite structure and the lattice constants a and c are 0.3265nm and 0.5218 nm respectively. Lattice constants a and c of the Mg0.33Zn0.67O film increased because of the addition of Mg. The image of SEM shows that the Mg0.33Zn0.67O film is homogeneous and its average grain size is about 40nm. The absorption spectrum of the sample reveals that the absorption edge of Mg0.33Zn0.67O film located at 312.3nm and the corresponding forbidden band width is 3.97eV. is by three peaks ，which located at 383.9nm，442.6nm and 532.9nm respectively，constitute the luminescence spectrum of the film. The excitation peak located at 379.9nm.

Structural and Morphological Studies of Cadmium Sulfide Nanostructures

2013 ◽  
Vol 795 ◽  
pp. 228-232 ◽  
Author(s):  
Abdulwahab S.Z. Lahewil ◽  
Y. Al-Douri ◽  
U. Hashim ◽  
Naser Mahmoud Ahmed
Keyword(s):  
Grain Size ◽  
Cadmium Sulfide ◽  
Spin Coating ◽  
Sol Gel ◽  
Theoretical Data ◽  
Glass Substrates ◽  
Morphological Studies ◽  
Average Grain Size ◽  
Cds Nanostructures ◽  
Semiconductor Properties

Cadmium sulfide (CdS) nanostructures were prepared with different spin coating speed 1000 and 3000 rpm and molarities of Cd:S to be 1.2 to 0.01 mol/L using sol-gel spin coating technique. It is found that the average grain size of CdS nanostructures deposited on glass substrates at 1000 and 3000 rpm is 43 to 4 nm respectively. The effect of grain size on the semiconductor properties are in agreement with experimental and theoretical data.

Sol-gel growth of Ni doped CdS on glass substrates: effect of spin coating speed and dopant concentration

2020 ◽  
Vol 10 ◽  
Author(s):  
Atefeh Nazari Setayesh ◽  
Hassan Sedghi
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Spin Coating ◽  
Optical Band Gap ◽  
Dopant Concentration ◽  
Rotation Speed ◽  
Sol Gel ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Glass Substrates

Background: In this work, CdS thin films were synthesized by sol-gel method (spin coating technique) on glass substrates to investigate the optical behavior of the film. Methods: Different substrate spin coating speeds of 2400, 3000, 3600 rpm and different Ni dopant concentrations of 0 wt.%, 2.5 wt.%, 5 wt.%) were investigated. The optical properties of thin films such as refraction index, extinction coefficient, dielectric constant and optical band gap energy of the layers were discussed using spectroscopic ellipsometry method in the wavelength range of 300 to 900 nm. Results: It can be deduced that substrate rotation speed and dopant concentration has influenced the optical properties of thin films. By decreasing rotation speed of the substrate which results in films with more thicknesses, more optical interferences were appeared in the results. Conclusion: The samples doped with Ni comparing to pure ones have had more optical band gap energy.

LiNiO2 Thin Films Fabricated by Diffusion of Li on Ni Tapes

2007 ◽  
Vol 336-338 ◽  
pp. 505-508
Author(s):  
Cheol Jin Kim ◽  
In Sup Ahn ◽  
Kwon Koo Cho ◽  
Sung Gap Lee ◽  
Jun Ki Chung
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Grain Size ◽  
Sol Gel ◽  
Surface Oxidation ◽  
Cold Isostatic Pressing ◽  
Tube Furnace ◽  
Treatment Conditions ◽  
Average Grain Size ◽  
Cold Rolling And Annealing

LiNiO2 thin films for the application of cathode of the rechargeable battery were fabricated by Li ion diffusion on the surface oxidized NiO layer. Bi-axially textured Ni-tapes with 50 ~ 80 μm thickness were fabricated using cold rolling and annealing of Ni-rod prepared by cold isostatic pressing of Ni powder. Surface oxidation of Ni-tapes were conducted using tube furnace or line-focused infrared heater at 700 °C for 150 sec in flowing oxygen atmosphere, resulted in NiO layer with thickness of 400 and 800 μm, respectively. After Li was deposited on the NiO layer by thermal evaporation, LiNiO2 was formed by Li diffusion through the NiO layer during subsequent heat treatment using IR heater with various heat treatment conditions. IR-heating resulted in the smoother surface and finer grain size of NiO and LiNiO2 layer compared to the tube-furnace heating. The average grain size of LiNiO2 layer was 0.5~1 μm, which is much smaller than that of sol-gel processed LiNiO2. The reacted LiNiO2 region showed homogeneous composition throughout the thickness and did not show any noticeable defects frequently found in the solid state reacted LiNiO2, but crack and delamination between the reacted LiNiO2 and Ni occurred as the reaction time increased above 4hrs.

scholarly journals The Influence of Annealing Temperature on the Structure and Magnetic Properties of Nanocrystalline BiFeO3 Prepared by Sol–Gel Method

2021 ◽  
Author(s):  
T. Pikula ◽  
T. Szumiata ◽  
K. Siedliska ◽  
V. I. Mitsiuk ◽  
R. Panek ◽  
...  
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Weak Ferromagnetism ◽  
X Ray Diffraction ◽  
Gel Method ◽  
Sol Gel Method ◽  
Average Grain Size ◽  
Spin Cycloid

AbstractIn this work, BiFeO3 powders were synthesized by a sol–gel method. The influence of annealing temperature on the structure and magnetic properties of the samples has been discussed. X-ray diffraction studies showed that the purest phase was formed in the temperature range of 400 °C to 550 °C and the samples annealed at a temperature below 550 °C were of nanocrystalline character. Mössbauer spectroscopy and magnetization measurements were used as complementary methods to investigate the magnetic state of the samples. In particular, the appearance of weak ferromagnetic properties, significant growth of magnetization, and spin-glass-like behavior were observed along with the drop of average grain size. Mössbauer spectra were fitted by the model assuming cycloidal modulation of spins arrangement and properties of the spin cycloid were determined and analyzed. Most importantly, it was proved that the spin cycloid does not disappear even in the case of the samples with a particle size well below the cycloid modulation period λ = 62 nm. Furthermore, the cycloid becomes more anharmonic as the grain size decreases. The possible origination of weak ferromagnetism of the nanocrystalline samples has also been discussed.

scholarly journals Effect of Solution Conditions on the Properties of Sol–Gel Derived Potassium Sodium Niobate Thin Films on Platinized Sapphire Substrates

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1600 ◽  
Author(s):  
Alexander Tkach ◽  
André Santos ◽  
Sebastian Zlotnik ◽  
Ricardo Serrazina ◽  
Olena Okhay ◽  
...  
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Low Cost ◽  
Sol Gel ◽  
Precursor Solution ◽  
Dissipation Factor ◽  
Solution Concentration ◽  
Potassium Sodium Niobate ◽  
Sapphire Substrates ◽  
Average Grain Size

If piezoelectric micro-devices based on K0.5Na0.5NbO3 (KNN) thin films are to achieve commercialization, it is critical to optimize the films’ performance using low-cost scalable processing conditions. Here, sol–gel derived KNN thin films are deposited using 0.2 and 0.4 M precursor solutions with 5% solely potassium excess and 20% alkali (both potassium and sodium) excess on platinized sapphire substrates with reduced thermal expansion mismatch in relation to KNN. Being then rapid thermal annealed at 750 °C for 5 min, the films revealed an identical thickness of ~340 nm but different properties. An average grain size of ~100 nm and nearly stoichiometric KNN films are obtained when using 5% potassium excess solution, while 20% alkali excess solutions give the grain size of 500–600 nm and (Na + K)/Nb ratio of 1.07–1.08 in the prepared films. Moreover, the 5% potassium excess solution films have a perovskite structure without clear preferential orientation, whereas a (100) texture appears for 20% alkali excess solutions, being particularly strong for the 0.4 M solution concentration. As a result of the grain size and (100) texturing competition, the highest room-temperature dielectric permittivity and lowest dissipation factor measured in the parallel-plate-capacitor geometry were obtained for KNN films using 0.2 M precursor solutions with 20% alkali excess. These films were also shown to possess more quadratic-like and less coercive local piezoelectric loops, compared to those from 5% potassium excess solution. Furthermore, KNN films with large (100)-textured grains prepared from 0.4 M precursor solution with 20% alkali excess were found to possess superior local piezoresponse attributed to multiscale domain microstructures.

SPECTROSCOPIC ELLIPSOMETRY INVESTIGATION ON OPTICAL PROPERTIES OF Fe:SNO2 THIN FILMS: EFFECTS OF IRON CONCENTRATION

2020 ◽  
pp. 2050044
Author(s):  
SAHAR MORADI ◽  
HASSAN SEDGHI
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Spectroscopic Ellipsometry ◽  
Sol Gel ◽  
Iron Concentration ◽  
Dielectric Constants ◽  
Bandgap Energy ◽  
Dispersion Parameters ◽  
Glass Substrates ◽  
Coating Method

Nanostructured Fe:SnO2 thin films were deposited on glass substrates through sol–gel spin coating method. Films were synthesized with different iron quantities including 0%, 4%, 8% and 12% (wt.%). The effects of Fe concentration on optical properties of films were investigated by spectroscopic ellipsometry (SE) technique. SE measured ([Formula: see text]) parameters for films in the wavelength range between 300[Formula: see text]nm to 800[Formula: see text]nm. Optical properties including the refractive index, extinction coefficient, transmittance, dielectric constants and optical conductivity were determined by fitting the SE measured ([Formula: see text]) parameters and data obtained from the optical model-based analysis. Results showed that the transmittance values increase by increment of Fe concentration from 0% to 12%. The bandgap energy ([Formula: see text] of prepared thin films was also calculated. [Formula: see text] values were between 3.44 and 3.58[Formula: see text]eV. Dispersion parameters including the high frequency dielectric constant ([Formula: see text] and the ratio of free carrier concentration to effective mass (N/m[Formula: see text] were then obtained for the prepared films.

The Effect of Sintering Temperature on the Crystal Structure and Luminescence Properties of Pr:LSO Polycrystalline Films

2016 ◽  
Vol 852 ◽  
pp. 1080-1086
Author(s):  
Xiao Xin Zhang ◽  
Jian Jun Xie ◽  
Ying Shi ◽  
Ling Cong Fan ◽  
De Bao Lin ◽  
...  
Keyword(s):  
Thin Film ◽  
Grain Size ◽  
Decay Time ◽  
Sintering Temperature ◽  
Coating Layer ◽  
Sol Gel ◽  
Characteristic Emission ◽  
Average Grain Size ◽  
Lutetium Oxyorthosilicate ◽  
Xrd Patterns

Lutetium oxyorthosilicate (Lu2SiO5, LSO) doped with Pr3+ was synthesized on cleaned silicon (111) substrates by sol-gel route with the spin-coating technique. XRD patterns indicated that the films were crystallized into A-type LSO phase at 1000 °C, followed by a phase transition to B-type LSO occurred at 1100 °C. SEM observations revealed that the surface of the films was smooth, homogeneous and crack-free. When the sintering temperature was 1000 °C, the average grain size of the crystal particles was 100-200 nm and the thickness of the thin film was about 380 nm when the coating layer number up to 10. While the sintering temperature was 1100 °C, the average grain size of the crystal particles was 200-300 nm and the thickness of the thin film was about 320 nm also 10 layers. PL spectra showed when under 1000 °C, the quenching concentration of Pr3+ was 0.3 mol%, the characteristic emission peaks was 289 nm and 340 nm and the dominant decay time was 4.64 ns; while under 1100 °C, the quenching concentration of Pr3+ was 0.4 mol%, the characteristic emission peaks was 280 nm and 320 nm and the dominant decay time was 2.61 ns.

Structural and Optical Properties of InSnO3 Sol-Gel Coatings to Use in Windows Glass Buildings

2010 ◽  
Vol 168-170 ◽  
pp. 2348-2351
Author(s):  
Lazaro De Jesus Dominguez Gallegos ◽  
Angélica Silvestre López Rodríguez ◽  
Pio Sifuentes Gallardo ◽  
Miguel Angel Hernández Rivera ◽  
María Guadalupe Garnica Romo ◽  
...  
Keyword(s):  
Optical Properties ◽  
Indium Tin Oxide ◽  
Sol Gel ◽  
Visible Region ◽  
Optical Transmittance ◽  
Indium Chloride ◽  
Glass Substrates ◽  
Tin Chloride ◽  
Ito Thin Films ◽  
Ito Films

Indium stannate (InSnO3) films doping with small amounts of copper are made highly useful as architectural window coatings. Indium-tin-oxide (ITO) has attracted intense interest due to some of its unique characteristics; it has high optical transmittance in the visible region, low electric resistivity, and chemical stability. Therefore, ITO thin films have been found to play an important role in opto-electronic applications. In this work, uniform and transparent ITO films were deposited onto glass substrates using a sol-gel process. The initial sols were prepared by mixing solutions of indium chloride prepared in anhydrous ethanol with tin chloride and mechanically stirring and refluxed 2 hours and aged 2 week, the resultant mixture until a clear and sticky coating sol was obtained. The glass substrates were spin-coated and annealed at 500 °C. Because annealing conditions affect the microstructures, the properties of the resultant ITO films can be controlled. The optical transmittance of 200 nm thick ITO film was more than 80% in the visible region. The surface morphology examined by SEM appears to be uniform over large surface areas. The structural, microstructural and optical properties of the coatings and powders made from the sols were extensively characterized by using XRD, AFM and spectrophotometer techniques

Self-Diffusion as A Limiting Factor of a-SiGe Crystallization

1997 ◽  
Vol 469 ◽  
Author(s):  
F. Edelman ◽  
T. Raz ◽  
Y. Komem ◽  
P. Werner ◽  
W. Beyer ◽  
...  
Keyword(s):  
Grain Size ◽  
Nanocrystalline Structure ◽  
Limiting Factor ◽  
In Situ Tem ◽  
Large Area ◽  
Self Diffusion ◽  
Glass Substrates ◽  
Vacancy Generation ◽  
Nonequilibrium Vacancy ◽  
Average Grain Size

ABSTRACTHighly doped (∼1018 to 1021cm−3) polycrystalline Si1-xGex films, crystallized from amorphous (a) state at relative low temperatures, are prospective materials in a variety of applications, such as liquid-crystal displays, solar cells and integrated thermoelectric sensors on large-area glass substrates. Since the nature of the grains in the crystallized film defines properties such as carrier mobility, the nucleation and growth process of the a-SiGe films is of fundamental interest. We have studied the crystallization of undoped and highly doped (B or Ga) amorphous SiGe films. The films were deposited by RFCVD or molecular beam on oxidized (001)Si and for TEM study on cleaved NaCl. The incubation time and grain growth rate were studied by means of in situ TEM using a heating stage. The crystallization process in undoped SiGe followed Avrami relationship. An average grain size between 0.1 and 2μm was observed. However, the highly p-doped (with B or Ga) SiGe films crystallized to a stable nanocrystalline structure (grain size <10nm). The process of the a-SiGe crystallization is explained on the basis of self-diffusion. During the first stage, the nucleation of crystals is accompanied with nonequilibrium vacancy generation at the amorphous/crystalline interface. During the second stage, the growth of crystals takes place by vacancy outdiffusion which is hindered by B and Ga interaction with vacancies.

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