Influence of substrate temperature on the structural and optical properties of crystalline ZnO films obtained by pulsed spray pyrolysis (original) (raw)
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The Pure zinc oxide (ZnO) thin films of different substrate temperature have been prepared on well cleaned glass substrate by improved spray pyrolysis technique. The gross structure of the annealed films have been examined by X-ray diffraction (XRD) technique using powder X-ray diffractometer which reveals the enhancement of crystallinity with increase in the deposition temperature. Surface morphology of the synthesized ZnO thin films have been analyzed by means of atomic force microscopy (AFM) which reveals average particle size of as synthesize ZnO thin films has been found to be 79 nm. The band gap as deposited ZnO have been examined by UV-Vis spectroscopy carried out in absorption mode by Double Beam UV-VIS Spectrophotometer with radiations in the range of í µí»= 190 nm to 1100 nm which is in the range of 3.03 eV to 3.16 eV.
International Letters of Chemistry, Physics and Astronomy, 2015
ZnO thin films deposited on various substrates including glass, quartz, and ITO (Indium Tin Oxide) coated on glass substrates have been conducted by (CSP) technique. Characterization techniques of X-ray diffraction (XRD), atomic force microscopy (AFM), UV-visible, and photoluminescence (PL) spectra measurements were performed to investigate the effects of substrate on the structural and optical properties of ZnO thin films. Samples were prepared the thickness of thin films are (80 nm) and substrate temperature kept at (400oC) in all cases. Compressed nitrogen was used as a carrier gas. The XRD results indicated that the synthesized ZnO thin films have a pure wurtzite (hexagonal phase) structure. It can be seen that the highest texture coefficient was in (002) plane . So when a good crystalline substrate like quartz is used for depositing the film, the lattice matching with the deposited film material would be better. AFM measurement showed the grain size ranging from (62-86) nm. The...
Annealing Effect on Structure and Optical Properties of ZnO Thin Films Prepared by Spray Pyrolysis
Polycrystalline films ZnO has been grown onto glass substrates by chemical spray pyrolysis (CSP) method. They were given heat treatment at different temperatures and constant time and for different times with constant temperature in air. The change in structural and optical properties was studied by means of X-ray diffraction (XRD), SEM, and optical absorption measurements. Structural analysis by X-ray diffraction pattern showed annealed ZnO film has high-orientation along c-direction (0 0 2), which remained the same with different heat treatment. The lattice constants of ZnO thin films were also obtained from XRD data. It is found that, with the increase of different heat treatments, the lattice constant a increases from 3.208 Å to 3.254 Å, and c increases from 5.125 Å to 5.219 Å. Where at higher annealing temperature and time the lattice constant c and a approach from bulk value. Other orientations corresponding to (1 0 0) and (1 0 1) are presented with very low relative intensities as compared to that of (0 0 2) plane. The transparency is increasing with increasing annealing temperature and time due to decreasing in films thickness with increasing annealing temperature and time. Change in bandgap energy from 3.2 to 3.01 eV was observed for different heat treatments.
Advanced Energy: An International Journal, 2015
ZnO thin film were deposited by spray pyrolysis on glass substrates, using zinc nitrate as precursor with different molar concentrations varying from 0.05M to 0.2 M. To study the structural proprieties of the film , the different technique was used as the X-ray diffraction, atomic force microscopy (AFM), Raman scattering , and FTIR. The optical properties were explored by transmission, reflectivity and Photoluminescence techniques. The ZnO thin films obtained in this paper are polycrystallines, the grain size increases when the molar concentration of Zn precursor was increasing. The films are transparent in visible region, this transmission values decreases when the molar concentration increase caused by the increasing of surface roughness
Influence of Thermal Process on Physical Properties of ZnO Films Prepared by Spray Pyrolysis
Acta Physica Polonica A, 2014
ZnO lms were deposited on glass substrates by ultrasonic spray pyrolysis technique at a substrate temperature of 300 ± 5 • C. All of the lms have been annealed at 500 • C temperature for dierent time (1, 2, and 3 h) to improve the optical, electrical and surface properties. The eect of annealing time on the lms of physical properties has been investigated. UV-Vis spectrophotometer has been used for transmittance measurements. Also, band gap values of the lms have been determined by optical method. Atomic force microscopy has been used to have information the surface morphology and roughness values of the lms. Thicknesses, refractive index and extinction coecient values of the lms have been determined by spectroscopic ellipsometry technique. The electrical conduction mechanisms and resistivity of the lms were investigated using two probe technique. After all the investigations it was concluded that annealing time has a dramatic eect especially on the surface, optical properties and electrical resistivity values of ZnO lms. From the results of these investigations, the application potential of the lms for solar cell devices as transparent electrode was searched.
American Journal of Nano Research and Applications
In the present work, zinc oxide (ZnO) thin films were deposited by pyrolysis spray technique on glass substrate temperature 350°C, using the zinc acetate with a molarity of 0.1M. Our interest is on the investigation of the nozzle-substrate distance on the structural and optical properties of the films. Structural analysis by X-ray diffraction showed that the deposited films have a preferred orientation along the direction (002) and are relatively uniform. The spectrophotometer UV-Visible confirms that it is possible to get good transparent ZnO films with a transmission of 80 to 95% in the visible. The values of optical gaps Eg deduced from the spectra of UV-Visible transmissions vary between 3.21 and 3.25 eV.
Contribution to the study of ZnO films properties prepared by spray pyrolysis
OPTOELECTRONICS AND ADVANCED MATERIALS-RAPID COMMUNICATIONS
Transparent conducting oxides (TCOs) are widely used as electrodes in optoelectronic devices due to their optical transparency in the visible range and to their electrical conductivity. They can be found in various applications such as photovoltaic solar cells, liquid crystal displays, sensors and organic light emitting devices. Indium tin oxide (ITO) and zinc oxide (ZnO) are the two major TCO materials to be used. In our case, we have deposited Zinc oxide onto pyrex substrates by Spray Pyrolysis technique at temperatures ranging from 350 to 450°C by step of 25°C. The structural properties of the films were studied by X-Ray diffraction (XRD) and confirmed by selected area electron diffraction (SAED) mode. Surface morphology of ZnO thin films was analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The films appear to be composed of ZnO nanoparticles (ZnO NPs), whom size increases with temperature. The results showed the presence of the wurtzite phase of ZnO with an orientation along the c-axis of the crystallites. Morphology images of the films obtained by Scanning electron microscopy revealed that pure ZnO film grew as quasi-aligned hexagonal shaped microrods with diameters varying between 100 and 400 nm. UV-visible spectroscopy measurements were also performed to determine the optical band gap.
Structural and microstructural investigations of ZnO thin films obtained by spray pyrolysis technique. In this paper ZnO thin films were obtained by using spray pyrolysis method at different temperatures of glass substrates. Properties were determined by X-ray diffraction method and scanning electron microscopy. Zinc acetate dihydrate dissolved in distilled water with a concentration of 0.3 M was used as an initial solution. The influence of substrate temperature on the grain size, phase structure, quality of films' texture, lattice constants, size of coherent scattering domains was discovered. The research results can be used in the development of functional solar cells layers.
Ceramics International, 2014
Sprayed ZnO films were grown on glass substrate at 400 1C using zinc chloride as precursor with different molar concentrations varying from 0.05 to 0.2 M. X-ray diffraction patterns reveal that ZnO films are polycrystalline with hexagonal wurtzite structure with preferred orientation in (002) plane. Optical measurements show that transmittance reaches a maximum value of 95% in the visible region for ZnO films prepared from precursor with 0.05 M concentration. The films obtained from the precursor with 0.1 M concentration have the highest electrical conductivity and photocurrent values.