Effect of indium doping in CdO thin films prepared by spray pyrolysis technique (original) (raw)
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Full Paper Structural, optical and electrical properties of indium doped cadmium oxide thin films
2013
Conducting and transparent indium doped CdO thin films were prepared by spray pyrolysis on a glass substrate with various concentration of indium (2-8 wt%) in the spray solution. The optical and structural properties of indium doped and undoped CdO films were studied utilizing optical transmission, X-ray diffraction and atomic force microscope. X-ray analysis shows that the doped and undoped CdO films are preferentially orientated along (111) crystallographic directions. Increase of indium doping concentration increases the films packing density and reorient the crys-tallites along (1 1 1) plane. There is a decrease in the optical transmissions for all films with the decrease in wavelength. The light transmission of CdO films increases as In doping level increases. The optical band gap value of CdO was equal to 2.55 eV and it was increase with doping concentration and reaches a maximum value of 2.65 eV at 4 wt% indium doping. Low resistivity achieved in the present study was found t...
Optical and Electrical Characteristics of CdO thin films deposited by Spray Pyrolysis Method
Journal of Bangladesh Academy of Sciences, 2009
Cadmium oxide (CdO) thin films have been deposited by a locally developed spray pyrolysis method onto glass substrate at 473K. The optical and electrical properties of the as-deposited and annealed films are studied in details. The surface morphology of the samples was studied by scanning electron microscopy (SEM). The SEM micrograph of as-deposited film shows uniform deposition over the substrate well. The optical absorption coefficient (α) of the CdO films was determined from transmittance spectra in the range of wavelength 450 - 650nm. For different thicknesses (130nm ~ 380nm) of as-deposited films, the direct band gap is found in the range of 2.40 ~2.51 eV and indirect band gap in the range of 1.97 ~ 2.20 eV. Resistivity (Ï) of CdO thin film was measured in the temperature range of 303 to 553K. The resistivity of the films of different thickness initially increases with increase in temperature and reaches a maximum at 430K and then decreases with further increase of temperatur...
Optical and electrical properties of CdO thin films deposited by spray pyrolysis method
Journal of Bangladesh Academy of Sciences
Cadmium oxide (CdO) thin films have been deposited by a locally developed spray pyrolysis method onto glass substrate at 473K. The optical and electrical properties of the as-deposited and annealed films are studied in details. The surface morphology of the samples was studied by scanning electron microscopy (SEM). The SEM micrograph of as-deposited film shows uniform deposition over the substrate well. The optical absorption coefficient (α) of the CdO films was determined from transmittance spectra in the range of wavelength 450-650nm. For different thicknesses (130nm ~ 380nm) of as-deposited films, the direct band gap is found in the range of 2.40 ~2.51 eV and indirect band gap in the range of 1.97 ~ 2.20 eV. Resistivity (ρ) of CdO thin film was measured in the temperature range of 303 to 553K. The resistivity of the films of different thickness initially increases with increase in temperature and reaches a maximum at 430K and then decreases with further increase of temperature. The resistivity of the film exhibits metallic behaviour up to 430 K and above that the film behaves like a semiconductor. Activation energy (∆E) in the semiconductor region is found in the range from 0.049 to 0.075 eV for films of thickness ranging from 160-285 nm.
IOSR Journals , 2019
Cadmium Oxide (CdO) and Al doped CdO semiconducting films have been fabricated onto glass substrate at temperature (330 ± 20) °C by chemical spray pyrolysis (CSP) technique using as a source material of cadmium acetate and aluminum chloride. The XRD study confirms that CdO and Al doped CdO thin films are polycrystalline in nature and can be indexed with cubic structure with (200) preferred orientation having lattice parameter of 0.4678 nm. The optical study showed that the films are highly transparent, above 85% transmission for wavelengths ≥ 900nm and the value of direct band gap has been decreases with the increase of Al doping concentration in CdO thin films and reaches a minimum of 2.43eV when doping level is 2 wt.%. The electrical conductivity increases with the increasing of doping level of Al in CdO thin films. A minimum resistivity of 3.79×10-4Ω-cm with carrier concentration of 1.30×1020 cm -3 is achieved when CdO film is doped with 2 wt.%. The measurement of thermoelectric power confirms that the thermal emf of CdO thin film increases with increasing temperature and the value is positive that indicates n type semiconducting nature of the film.
Synthesis and characterization of CdIn2O4 thin films by spray pyrolysis technique
Journal of Alloys and Compounds, 2009
Transparent conducting cadmium indium oxide (CIO) thin films were deposited onto preheated glass substrates by using spray pyrolysis technique with cadmium acetate and indium acetate as precursors for Cd and In ions, respectively. The films have been deposited at various substrate temperatures within 250-325 • C. As-deposited films were annealed at optimized temperature of 400 • C for 2 h in order to enhance the film properties under ambient air atmosphere. These films were characterized by X-ray diffraction (XRD), SEM, optical absorption and Hall effect techniques. The XRD studies reveal that films are of polycrystalline CdIn 2 O 4 with cubic spinel structure and crystallinity increases appreciably after annealing. Optical absorption study shows the presence of direct optical transition and the band gap energy, estimated for as-deposited and annealed films were observed to be 3.1 and 3.0 eV, respectively. The decrease of electrical resistivity from 91.2 × 10 −3 to 1.92 × 10 −3 cm have been observed after annealing, due to improvement in the crystallinity of the films. The highest figure of merit observed in the present study is 4.51 × 10 −3 cm 2 −1 .
In doped CdO films: Electrical, optical, structural and surface properties
International Journal of Hydrogen Energy, 2009
Recently, there has been a lot of work on the production and investigation of the physical properties of Transparent Conducting Oxide (TCO) materials which have common application area in photovoltaic solar cells and some optoelectronic devices. In this work, CdO film which is a material belongs to TCO family has been produced by Ultrasonic Spray Pyrolysis technique on microscope glass substrates at the substrate temperature of 250 AE 5 C. Electrical, optical, structural and surface properties of undoped and In doped (at 1.3 and 5%) CdO films and the effect of In doping percentage on the physical properties of CdO films have been investigated. It has been determined that electrical conductivity of CdO film is high and this value has been decreased by In doping. After the optical investigations, it has been observed that the transmittances of the films are about 30% and decreased dramatically by In doping. XRD investigations showed that, films have polycrystalline structure and good crystallinity levels. It has been found that In element hasn't got an important effect on the morphology of the films after the examination of surface micrographs. It has been determined that Cd and O elements are present in the solid film by using EDS. After all investigations, it has been concluded that In doping has an important effect on the electrical, optical, structural and surface properties of CdO films.
Cadmium oxide transparent thin film is deposited by spray pyrolysis technique on glass subtract at 4000C and annealed at a temperature of 100 °C for one hour. The band gap was found depend on varius parameters is studied. It is noted that the shift in band gap i.e. decrease with the increasing film thickness in the range 2.15 eV to 2.40 eV. The optical constants such as, band gap, refractive index, extinction coefficient as a function of photon energy for all prepared films were calculated. also studied The XRD revealed of thin film of CdO shows polycrystalline in nature
2014
Cadmium oxide (CdO:2%In) thin films have been deposited onto glass substrates from different molar concentration of cadmium acetate precursor solution using a simple spray pyrolysis technique. The structural and optical properties of the films have been characterized by X-ray diffraction study and UV spectroscopy. The crystal structure of the deposited films were found to be polycrystalline of cubic structure with preferentially orientated along (111) crystallographic directions. Increase of molar concentration increases the films packing density and reorient the crystallites along (1 1 1) plane. There is an ancease in the optical transmissions for all films with increasing in the wavelength and molar concentration . For different molar concentrations (0.1M ,0.2 M, and 0.3M), the direct band gap is found to be in the range( 2.3 ,2.35,and 2.45 eV) . The band gap energies depend on molar concentration of solution.