Optical properties of PVP/ZnO composite thin films

2017 ◽  
Vol 1 (82) ◽  
pp. 5-11 ◽  
Author(s):  
T. Tański ◽  
W. Matysiak
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Zno Nanoparticles ◽  
Energy Band ◽  
Composite Coatings ◽  
Energy Band Gap ◽  
Thin Coatings ◽  
Pure Polymer ◽  
Vis Spectroscopy ◽  
Coating Method

Purpose: The aim of the work was the preparation of thin composite layers from PVP polymer doped by ZnO nanoparticles using the spin coating method and the analysis of the applied reinforcing phase on the morphology and optical properties of obtained composites. Design/methodology/approach: To analyse the morphology of thin coatings a technique of surface topography imaging using the atomic force microscopy (AFM) was applied. Analysis of the optical properties was conducted using absorbance spectrum in function of wavelength for all produced thin coatings using UV-Vis spectroscopy. Findings: AFM results show that mass concentration of ZnO nanoparticles of 10% in a solution of PVP/EtOH polymers has a meaningful influence on the morphology of the surface of the PVP/ZnO composite coatings. Using obtained absorbance spectra, the width of the band gap of the manufactured composite coatings were determined which were compared with a band gap values of pure polymer and used reinforcing phase. Practical implications: The analysis of the values of the energy band gap of the manufactured materials showed that both for pure polymer and composite coatings values of energy band gap are similar approx. 4 eV at the same time decrease the degree of absorption of electromagnetic radiation caused by the increasing concentration of the reinforcing phase, which indicates the broad possibilities of application of this type of the material.

scholarly journals Effect of Dopant Concentration on the Structural, Optical and Sensing Properties of (SnO2)1-x(TiO2:CuO)x Sprayed Films

2019 ◽  
Vol 16 (2) ◽  
pp. 0361
Author(s):  
Mahmood Et al.
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Energy Band ◽  
Spray Pyrolysis Technique ◽  
Single Crystal Silicon ◽  
Dielectric Constants ◽  
Energy Band Gap ◽  
Crystal Silicon ◽  
X Ray ◽  
Regular Manner

      Spray pyrolysis technique was subjected to synthesized (SnO2)1-x (TiO2: CuO) x Thin films on different substrates like glass and single crystal silicon using. The structure of the deposited films was studied using x-ray diffraction. A more pronounced diffraction peaks of SnO2 while no peaks of (CuO , TiO2 ) phase appear in the X-ray profiles by increasing of the content of (TiO2 , CuO) in the sprayed films. Mixing concentration (TiO2 , CuO) influences on the size of the crystallites of the SnO2 films ,the size of crystallites of the spray paralyzed oxide films change in regular manner by increasing of (TiO2 , CuO) amount. The effect of mixing concentration on the optical properties of the films was also investigated. The reflectance and transmittance spectra  in the wavelength range (300-1100) nm were employed to determine the optical properties such as energy band gap (Eg) and refractive index (n),  extinction coefficient  (k) , real and imaginary parts of dielectric constants (ε1, ε2) for (SnO2)1-x(TiO2:CuO)x films. The energy band gap omit of which showed reduction from (3.65 to 2.2) eV by reducing of SnO2 amount from (100 to 70) % .The reduction of energy band gap was ascribed to the new tail states introduced in the band gap of tin oxide. The sensitivity of the prepared sensor film was determined resistance difference of the films when exposed to oxidizing gas. The data declared that the mixed SnO2 films have better sensitivity in comparison with unmixed films.

scholarly journals Preparation and Photocatalytic Properties of CdS and ZnS Nanomaterials Derived from Metal Xanthate

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3313 ◽  
Author(s):  
Neli Mintcheva ◽  
Gospodinka Gicheva ◽  
Marinela Panayotova ◽  
Wilfried Wunderlich ◽  
Aleksandr A. Kuchmizhak ◽  
...  
Keyword(s):  
Visible Light ◽  
Band Gap ◽  
Energy Band ◽  
Photocatalytic Properties ◽  
Cubic Phase ◽  
Sulfur Source ◽  
Energy Band Gap ◽  
Simple Method ◽  
Vis Spectroscopy ◽  
Metal Xanthate

In this paper, we report a new, simple method for the synthesis of CdS and ZnS nanoparticles (NPs) prepared in a basic aqueous medium using metal xanthate as the sulfur source. The structure, morphology, size distribution, optical band gap, and photocatalytic properties of the newly obtained nanomaterials were investigated by UV-Vis spectroscopy, X-ray diffraction, and transmission electron microscopy. The results show that both CdS and ZnS crystallized in cubic phase and formed NPs with average sizes of 7.0 and 4.2 nm for CdS and ZnS, respectively. A blue shift of UV-Vis absorbance band and higher energy band gap values were observed for both materials in comparison with their bulk counterparts, which is in accordance with the quantum confinement effect. The as-prepared nanomaterials were tested in visible-light driven photocatalytic decomposition of methylene blue (MB). After irradiation for 180 min, the degradation rate of MB with a concentration of 8 × 10−6 mol/L mixed with a photocatalyst (CdS or ZnS, both 10 mg in 100 mL solution of MB) was found to be 72% and 61%, respectively. The CdS NPs showed better photocatalytic activity than ZnS, which could be explained by their lower energy band gap and thus the ability to absorb light more efficiently when activated by visible-light irradiation.

STRUCTURAL, ELASTIC, ELECTRONIC, CHEMICAL BONDING AND OPTICAL PROPERTIES OF M2Se (M = Li, Na, K, Rb) THROUGH FIRST PRINCIPLE STUDY

2013 ◽  
Vol 27 (30) ◽  
pp. 1350170 ◽  
Author(s):  
ROSHAN ALI ◽  
R. KHANATA ◽  
BIN AMIN ◽  
G. MURTAZA ◽  
S. BIN OMRAN
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Chemical Bonding ◽  
Energy Band ◽  
Electronic Band Structure ◽  
Full Potential ◽  
Energy Band Gap ◽  
Electronic Band ◽  
Direct Energy ◽  
Metal Selenides

Structural, elastic, electronic and optical properties as well as chemical bonding of the binary alkali metal selenides M 2 Se ( M = Li , Na , K , Rb ) were calculated using the full potential linearized augmented plane method. From the elastic constants it is inferred that these compounds are brittle in nature. The results of the electronic band structure show that Na 2 Se has a direct energy band gap (Γ-Γ), Li 2 Se has an indirect energy band gap (Γ- X), while K 2 Se and Rb 2 Se have an indirect energy band gap (X-Γ). Analysis of the charge distribution plots reveals a dominated ionic bonding in the herein studied compounds. Additionally, we have calculated the optical properties, namely, the real and the imaginary parts of the dielectric function, refractive index, extinction coefficient, optical conductivity and reflectivity for radiation up to 30.0 eV. All these compounds have direct energy band gap greater than 3.1 eV suggesting their use for manufacturing high frequency devices.

Characterization of Tb-doped hydroxyapatite for biomedical applications: optical properties and energy band gap determination

2017 ◽  
Vol 52 (17) ◽  
pp. 9990-10000 ◽  
Author(s):  
Y. Jiménez-Flores ◽  
M. Suárez-Quezada ◽  
J. B. Rojas-Trigos ◽  
L. Lartundo-Rojas ◽  
V. Suárez ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Energy Band ◽  
Biomedical Applications ◽  
Energy Band Gap

The Study of Energy Band Gap of In[sub x]Al[sub y]Ga[sub 1−x−y]N Quaternary Alloys using UV-VIS Spectroscopy

2009 ◽  
Author(s):  
N. H. Abd. Raof ◽  
S. S. Ng ◽  
H. Abu Hassan ◽  
Z. Hassan ◽  
Mohamad Rusop ◽  
...  
Keyword(s):  
Band Gap ◽  
Energy Band ◽  
Energy Band Gap ◽  
Quaternary Alloys ◽  
Vis Spectroscopy

Structural and optical properties of PbI2 nanostructures obtained using the thermal evaporation method

2013 ◽  
Vol 91 (10) ◽  
pp. 826-832 ◽  
Author(s):  
Safaa I. Mohammed ◽  
Y. Al-Douri ◽  
U. Hashim ◽  
N.M. Ahmed ◽  
R. Al-Gaashani
Keyword(s):  
Grain Size ◽  
Optical Properties ◽  
Band Gap ◽  
Energy Band ◽  
Room Temperature ◽  
Crystal Size ◽  
Thermal Evaporation ◽  
Energy Band Gap ◽  
Thermal Evaporation Method ◽  
Evaporation Method

Lead iodide (PbI2) nanostructures were successfully prepared using the thermal evaporation method on a glass substrate at room temperature. The structural properties were analyzed using X-ray diffraction, which revealed that the crystal size increases as thickness increases. Crystal size was calculated to be in the range 27.3–61.08 nm. In addition, the preferred growth orientation was (001) for all samples. The surface morphologies using scanning electron microscopy have shown an increasing of grain size with increasing thickness. Also, optical properties using ultraviolet–visible spectroscopy were researched as a function of thickness. The absorption data have indicated direct transmission with optical energy band gap that varies continuously from 2.35 to 2.40 eV at room temperature. The refractive index and optical dielectric constant were investigated to verify the suitability of the model for electro-optical systems. The low fluctuation in energy band gap indicates that the grain size is quite small. The obtained results are in good agreement with experimental and theoretical data.

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