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Subject: search.filters.subject.Spray pyrolysis

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    Investigations on electrical properties of the CdxZn 1-xS thin films prepared by spray pyrolysis technique
    (2011) Raviprakash, Y.; Bangera, K.V.; Shivakumar, G.K.
    Thin films of CdxZn(1-x)S (0≤x≤1) were deposited on glass substrates by the chemical spray pyrolysis technique. The electrical properties of these films in relation with composition were studied in detail. The entire investigation was made for a wide range of compositions of CdxZn(1-x)S thin films (x=0 to 1 in steps of 0.1). The variations of conductivity and current-voltage characteristics of these films were investigated as a function of the temperature and applied voltage. The activation energy of the films was found to vary from 0.35 eV to 0.78 eV. © 2011 American Institute of Physics.
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    X-ray diffraction studies of CdxZn1-xS thin films prepared by spray pyrolysis technique
    (2013) Raviprakash, Y.; Bangera, K.V.; Shivakumar, G.K.
    Thin films of CdxZn(1-x)S (0 ≤ x ≤ 1) were deposited on glass substrates by the chemical spray pyrolysis technique using a less used combination of chemicals. The variation of structural properties of these films in relation with composition was studied in detail. The entire study was made for a wide range of compositions of CdxZn (1-x) S thin films (x=0 to 1 in steps of 0.1). XRD studies reveal that all the films are polycrystalline with hexagonal (wurtzite) structure of which reflection peaks associated with (100), (002) and (110) planes were clearly identified for all the films and inclusion of cadmium into the structure of ZnS improved the crystallinity of the films. The value of lattice constants 'a' and 'c' was found to vary with composition from 0.382 to 0.415 nm and 0.625 to 0.675 nm respectively. © (2013) Trans Tech Publications, Switzerland.
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    Effect of substrate temperature on the structural and electrical properties of spray deposited lead sulfide thin films
    (Elsevier Ltd, 2016) Veena, E.; Bangera, K.V.; Shivakumar, G.K.
    Lead sulfide (PbS) thin films were prepared by chemical spray pyrolysis method using lead acetate and thiourea as precursors of Pb+2 and S-2 ions. X-ray diffraction (XRD) technique, scanning electron microscope (SEM) and EDAX analysis were used for structural, morphological and compositional characterization. XRD analysis shows that the films are cubic in nature with a preferred orientation along (2 0 0). EDAX analysis shows that films deposited at 150°C are sulfur rich. An increase in the substrate temperature results in a decrease in the sulfur content of the prepared film. It has been observed that thin films deposited at or above 225°C are smooth & uniform morphologically. Beyond a substrate temperature of 275°C, the films become discontinuous and non-uniform. However, the films are sulfur rich, even at 275°C. Electrical conductivity of prepared thin films have been measured using silver contacts in coplanar geometry. Films are n - type as confirmed by hot probe technique. The electrical conductivity at room temperature (25°C) was in the order of 10-4 Ω-1cm-1 and was found to increase with increase in temperature showing the semiconducting nature of the films with the band gap of 0.39 eV. © 2016 Elsevier Ltd.
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    Preparation and characterization of CdxZn1-xS thin films by spray pyrolysis technique for photovoltaic applications
    (2009) Raviprakash, Y.; Bangera, K.V.; Shivakumar, G.K.
    CdxZn(1-x)S (x = 0, 0.2, 0.4, 0.6, 0.8, and 1) thin films were deposited by the chemical spray pyrolysis technique using a less used combination of chemicals. Depositions were done at 573 K on cleaned glass substrates. The composition, surface morphology and structural properties of deposited films were studied using EDAX, SEM and X-ray diffraction technique. XRD studies reveal that all the films are crystalline with hexagonal (wurtzite) structure and inclusion of Cd into the structure of ZnS improved the crystallinity of the films. In the entire compositions, the (0 0 2) diffraction peak is prominent which gives lattice matching to the chalcogenide semiconductor such as CuInxGa1-xSe2 and CuIn (s1-xSex)2, which are used in photovoltaic devices. The value of lattice constant 'a' and 'c' have been observed to vary with composition from 0.382 to 0.415 nm and 0.625 to 0.675 nm, respectively. The band gap of the thin films varied from 3.32 to 2.41 eV as composition varied from x = 0.0 to 1.0. It was observed that presence of small amount of cadmium results in marked changes in the optical band gap of ZnS. © 2009 Elsevier Ltd. All rights reserved.
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    Growth, structural and optical properties of CdxZn1-xS thin films deposited using spray pyrolysis technique
    (2010) Raviprakash, Y.; Bangera, K.V.; Shivakumar, G.K.
    CdxZn(1-x)S (x = 0, 0.2, 0.4, 0.6, 0.8, and 1) thin films were deposited by the chemical spray pyrolysis technique using a less used combination of chemicals. Depositions were done at 573 K on cleaned glass substrates. The composition, surface morphology and structural properties of deposited films were studied using EDAX, SEM and X-ray diffraction technique. XRD studies reveal that all the films are crystalline with hexagonal (wurtzite) structure and inclusion of Cd into the structure of ZnS improved the crystallinity of the films. The value of lattice constant 'a' and 'c' have been observed to vary with composition from 0.382 to 0.415 nm and 0.625 to 0.675 nm, respectively. The band gap of the thin films varied from 3.32 to 2.41 eV as composition varied from x = 0.0-1.0. It was observed that presence of small amount of cadmium results in marked changes in the optical band gap of ZnS. © 2009 Elsevier B.V. All rights reserved.
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    Properties of ZnO:Bi thin films prepared by spray pyrolysis technique
    (Elsevier Ltd, 2013) Sadananda Kumar, N.; Bangera, K.V.; Anandan, C.; Shivakumar, G.K.
    Undoped and Bi doped zinc oxide thin films were deposited on glass substrate at 450 °C using spray pyrolysis technique. The X-ray diffraction studies shows that Bi doped ZnO films are polycrystalline hexagonal structure with a preferred orientation along (101) direction. Crystallites size of the films decreases with increasing doping concentration. Scanning electron microscope image shows change in the surface morphology. The composition of Zn, O and Bi elements in the undoped and Bi doped ZnO films were investigated by X-ray photoelectron spectroscopy. Bi doped ZnO thin films show a transparency nearly 75% in the visible region. The optical band gap of ZnO thin films reduces from 3.25 eV to 3.12 eV with an increase in Bi concentration from 0 to 5at.% respectively. Electrical conductivity of ZnO thin films increased from 0.156 to 6.02S/cm with increasing Bi dopant concentration from 0% to 5% respectively. © 2013 Elsevier B.V. All rights reserved.
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    Effect of annealing on the properties of Bi doped ZnO thin films grown by spray pyrolysis technique
    (Academic Press, 2014) Sadananda Kumar, N.; Bangera, K.V.; Shivakumar, G.K.
    The effect of annealing temperature on the structural, optical and electrical properties of transparent and conducting Bi doped ZnO (BZO) films deposited on glass substrate by spray pyrolysis technique was investigated. The BZO thin films were annealed in the temperature range from 450 °C to 550°C for 4 h in air atmosphere. The grain size of the BZO films increased with increasing annealing temperature. The annealed BZO films were electrically stable and there was a drastic change in the electrical conductivity after annealing. The films annealed at 500°C showed better conductivity and optical transmittance. © 2014 Elsevier Ltd. All rights reserved.
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    Effect of annealing on the properties of zinc oxide nanofiber thin films grown by spray pyrolysis technique
    (Springer Nature, 2014) Sadananda Kumar, N.; Bangera, K.V.; Shivakumar, G.K.
    Zinc oxide nanofiber thin films have been deposited on glass substrate by spray pyrolysis technique. The X-ray diffraction studies revealed that the films are polycrystalline with the hexagonal structure and a preferred orientation along (002) direction for films annealed for 1 h at 450 °C. Further increase in annealing time changes the preferred orientation to (100) direction. The scanning electron microscopic analysis showed the formation of ZnO nanofiber with an average diameter of approximately 800 nm for annealed films. The compositional analysis of nanofiber ZnO thin films were studied by time of flight secondary ion mass spectroscopy, which indicated oxygen deficiency in the films. The optical properties of annealed films have shown a variation in the band gap between 3.29 and 3.20 eV. The electrical conductivity of the as grown and annealed films showed an increase in the conductivity by two orders of magnitude with increase in annealing duration. © 2013, The Author(s).
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    Properties of CdxZn1-xO thin films and their enhanced gas sensing performance
    (Elsevier Ltd, 2017) Bharath, S.P.; Bangera, K.V.; Shivakumar, G.K.
    CdxZn1-xO(0 ? x ? 0.20) thin films with different Cd concentrations were successfully deposited on glass substrate using spray pyrolysis technique. X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDAX) were used for structural, surface morphological and compositional characterization. The XRD analysis revealed that the synthesized films were hexagonal in structure with (002) orientation. The SEM studies confirm the formation of homogeneous and uniform films. Optical transmittance and electrical conductivity of the films were evaluated using UV–Visible spectroscopy and two probe method respectively. The optical studies showed that the CdxZn1-xO thin films have optical transmittance in entire visible region. The resistivity of undoped films were very high and it decreases with addition of cadmium. The gas sensing properties were investigated at optimal temperature of 350 °C for various volatile organic compounds like acetone, ethanol and methanol. The CdxZn1-xO thin films with 10 at. % cadmium concentration showed the sensitivity of 50% for 1 ppm ethanol. © 2017 Elsevier B.V.
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    Effect of annealing on the properties of spray-pyrolysed lead sulphide thin films for solar cell application
    (Springer Verlag service@springer.de, 2017) Veena, E.; Bangera, K.V.; Shivakumar, G.K.
    Annealing is the most important processing parameter perhaps as it directly affects the properties of the thin films. In the present article, lead sulphide thin films composed of (2 0 0) plane-oriented nano-rods were successfully synthesized on glass substrates using spray pyrolysis technique at annealing temperature 350 °C. Films were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive analysis by X-ray (EDAX), UV–VIS–NIR spectrometry and two-probe experiments. The X-ray diffraction study confirmed that films exhibiting face-centred cubic structure with a preferred orientation along (2 0 0) plane were independent of annealing temperature. SEM photographs revealed the formation of nano-rods. The possible formation of nano-rods and its dependency on optical and electrical properties were discussed. Chemical composition in terms of atomic ratio of the constituents is determined from EDAX studies. The optical band gap of the lead sulphide thin films was found to decrease from 1.22 to 0.98 eV with an increase in annealing temperature. The electrical conductivity of the films at room temperature was of the order of 10?2 ??1 cm?1 with the low activation energy. Results prove that lead sulphide films grown by chemical method appeal its adoptability for potential solar cell applications. © 2017, Springer-Verlag Berlin Heidelberg.