Preparation and Studying the Optical Properties of (Sb2o3) Thin Films

In this paper I present the preparation of (Sb2o3) thin films using thermal evaporation in vacuum, procedure with different thickness (100 ,150 ,200 ,and 250) nm, by using ( hot plate) from Molybdenum matter at temperature in ( 900c) and the period of time (15mint) ,the prepared in a manner thermal evaporation in a vacuum and precipitated on glass bases, pure Antimony Trioxide (sb2o3 ) thin films with various condition have been successfully deposited by (T.E.V) on glass slide substrates. The substrates temperature of about 100C and the vacuum of about 10 torr, to investigated oxidation of evaporated, measure spectra for prepared films in arrange of wavelength (250 – 1100 nm). The following optical properties have been calculated : the absorption coefficient , the forbidden (Eg) for direct and indirect transitions "absorbance, refractive index, extinction coefficient, real and imaginary parts" of the dielectric constant. 1.Introduction Pure Antimony is a metal that manifests naturally in the earth’s crust, the most important mercantile compound derived from antimony is antimony trioxide ordinarily known as "ATO", chemical formula Sb2O3 . ATO is utilized in a wide diversity of industrial applications, fundamentally as a “synergist” with flame dilatory chemicals and as a catalyst in the industry of polyester. The total global exhaustion of "ATO" in 2010 was approximately 125.000 tons [1]. Antimony trioxide (Sb2O3) is solid and is commercialized as a white, scentless, crystalline powder, founded on "handbook-data", the melting point is(655°C) and effervescence point is (1550°C), and vapor compression at ambient temperature is deemed to be very small [2]. Over the last few contracts, fire integrity in our homes and public places have amended greatly, thanks mainly to international calibration efforts in electrical and electronic tools. Antimony Trioxide (sb2o3 ) very promote the efficiency of flame retardants, when used as a component in combination with halogenated flame retardants in plastics, dyeing, adhesives, rubber and textile back coatings[3]. Antimony Trioxide (sb2o3 ) is so used in numerous appliances within our house and offices; Tvs, computers, processing electrical assembly, optical cables, mains modifier and portable electronics and to fire safe plastic wraps, resin circuit boards. Antimony Trioxide (sb2o3 ) is not acutely poisonous, It is not considered toxic via inhalation or oral ingestion [4], [5]. For the evolution of such optical devices, Antimony Trioxide (sb2o3) thin films require thorough optical description. There are a number of physical and chemical routes for preparing (sb2o3 ) thin films. These include , sol-gel spin coating method, the evaporation method, spray pyrolysis, chemical bath deposition, etc [6]. The research on the optical characteristic of Antimony Trioxide (sb2o3 ) has attracted much notice in view of their wide application in optical devices and electronic equipment. The optical properties are calculated to check polarization properties , interference and better reflection [7]. In a group of former papers ,we include reported the structural and electrical properties of several (V–VI) semiconducting components "Sb2O3 and Sb2S3" in thin films. This paper concentrates on the test of optical properties of (Sb2O3) thin films prepared by (TVET) [8]. 2.Experimental Details High purity (99.99% purity from Merck) antimony trioxide (sb2o3 ) from J . M. (United Kingdom) was used in the thin films making ready. The antimony trioxide (sb2o3 ) powder settled in a ( vacuum deposition chamber ) for the production of thin film. The vaporization was loaded out in a classical vacuum coating unit (inficon V90) beneath a vacuum of arequest of( 6×10 torr). A molybdenum box was used as the vaporization container and the glass layers were cleaned at (100 ° C),where it was placed directly above the source with a displacement of almost (18cm). The glass substrates were cleaned with solution distilled water. Films of various thickness deposition were intended through Journal of University of Babylon for Pure and Applied Sciences (JUBAS) by University of Babylon is licened under a Creative Commons Attribution 4.0 International License. 2018.

Over the last few contracts, fire integrity in our homes and public places have amended greatly, thanks mainly to international calibration efforts in electrical and electronic tools. Antimony Trioxide (sb 2 o 3 ) very promote the efficiency of flame retardants, when used as a component in combination with halogenated flame retardants in plastics, dyeing, adhesives, rubber and textile back coatings [3]. Antimony Trioxide (sb 2 o 3 ) is so used in numerous appliances within our house and offices; Tvs, computers, processing electrical assembly, optical cables, mains modifier and portable electronics and to fire safe plastic wraps, resin circuit boards. Antimony Trioxide (sb 2 o 3 ) is not acutely poisonous, It is not considered toxic via inhalation or oral ingestion [4], [5]. For the evolution of such optical devices, Antimony Trioxide (sb 2 o 3 ) thin films require thorough optical description. There are a number of physical and chemical routes for preparing (sb 2 o 3 ) thin films. These include , sol-gel spin coating method, the evaporation method, spray pyrolysis, chemical bath deposition, etc [6].
The research on the optical characteristic of Antimony Trioxide (sb 2 o 3 ) has attracted much notice in view of their wide application in optical devices and electronic equipment. The optical properties are calculated to check polarization properties , interference and better reflection [7]. In a group of former papers ,we include reported the structural and electrical properties of several (V-VI) semiconducting components "Sb 2 O 3 and Sb 2 S 3 " in thin films. This paper concentrates on the test of optical properties of (Sb 2 O 3 ) thin films prepared by (TVET) [8].

2.Experimental Details
High purity (99.99% purity from Merck) antimony trioxide (sb 2 o 3 ) from J . M. (United Kingdom) was used in the thin films making ready. The antimony trioxide (sb 2 o 3 ) powder settled in a ( vacuum deposition chamber ) for the production of thin film. The vaporization was loaded out in a classical vacuum coating unit (inficon V90) beneath a vacuum of arequest of( 6×10 -6 torr). A molybdenum box was used as the vaporization container and the glass layers were cleaned at (100 ° C),where it was placed directly above the source with a displacement of almost (18cm). The glass substrates were cleaned with solution distilled water. Films of various thickness deposition were intended through different singular evaporations. Film thickness was measured after evaporation by optical interferometer system, using ( He-Ne Laser λ =0.632 µm) and determined the thickness according to:

Results and Discussion
ultra-violet-vis spectroscopy corresponds to electronic excitement between the energy levels linked to the molecular orbital of the system. (U.V-vis) spectra of all thin films are registered at the hall (T) in the framework of (200-1100) nm , and the absorbance spectra of antimony trioxide (sb 2 o 3 ) thin films as shown in figure (3.1), it is clearly seen that growing the absorbance with increased thickness of thin films .
show the transmittance spectrum in the rang (200-1100)nm, exhibit very small transmittance in the ultra-violet range while in the visible range and the near infrared regions showed very high transmittance to all thin films. Consequently these materials are considered as an optically transparent in the visible region [9]. The transmittance percent decreases with increasing thickness of thin films.

R + T + A = 1 ………………………………. (2)
Where: R is the reflectance. The ( R) of Sb 2 O 3 thin films is low in close to the infrared and visual area , this is can be attributed to the low absorbance in the (vis. and infr. region). The overall ( R) increases with the film thickness in the "vis. and infrared" region. The ( R) spectra of the films are showing the customary interference modality in the R spectra.

αhυ = B ( h υ -E gopt. ) r ..………………………………..(5)
Where: E gopt. : optical energy gap, ' B ' constant rely on the nature of the material, ' r ' exponential constant, depends on the transition method, for the allowed direct transition give( r =1/2 ) , for the forbidden direct transition give( r = 3/2 ) [16].   Figure (3.6)show the relationship between extinction coefficient (k) and wavelength for Sb 2 O 3 thin films deposited at different thickness. From the figure it showed that the extinction coefficient (k) is clearly affected by the thickness of thin films, but (k) increases with increasing of the thickness of thin films. This is refered to increased (α) with increased thickness of thin films [17] [18] .extinction coefficient (k) is given by the following equation:

………………….………….…… (6)
Where ( λ ) : is the wavelength of fallen photon rays.  " Where ' R' : is the reflectance". Figures (3.8) and (3.9) shows the variations in the (ε 1 and ε 2 ) parts of the dielectric constant with the wavelength for the (sb 2 o 3 ) thin films with difference thickness. Natural changes were observed depending on the thickness the films, the curves values of (ε 1 ) for the films of different thicknesses in the visible and infrared region. The (ε 2 ) prove the free carrier's contribution to the (A), the 'ε 1 ' is increased with the increase of difference thickness. The (ε 1 and ε 2 ) parts of the dielectric constant were specified using the relation :-

Conclusions
Sb 2 O 3 thin films with the thickness of (100 ,150, 200 and 250) nm where glass slides were present in the way of thermal evaporation in the vacuum (6×10 -6 torr), sedimentation conditions have an effect on transmission spectra, such as substrate temperature. We see higher transmittance of films when their thickness decreases. It was found that transmittance, absorbance and E gopt. , Eg, depend markedly on the thickness of the films.
The absorbance and absorption coefficient for Sb 2 O 3 thin films increases with the increasing of the film thickness. The transmittance decreases with increasing film thickness.( n , k and dielectric constant ℇ 1, ℇ 2 ) are increasing with the increase the film thickness. The ( Eg ) for indirect transition allowed, forbidden decreases with the increasing of the film thickness . The high transmittance of wavelengths in the ( vis. and near infr.) regions and the high absorbance in the ( ult-v. ) region offered the possibility of using Sb 2 O 3 films in various fields including, laser visible diodes and ultraviolet filters , fire safe plastic casings , switches , resin circuit boards and microsensors components.