Effects of Mn Doping on Zinc Oxide Films Prepared by Spray Pyrolysis Technique

2017 ◽  
Vol 16 (01) ◽  
pp. 1650024
Author(s):  
Bhavana Singh ◽  
S. B. Shrivastava ◽  
V. Ganesan
Keyword(s):  
Grain Size ◽  
Zinc Oxide ◽  
Spray Pyrolysis ◽  
Optical Measurement ◽  
Spin Fluctuation ◽  
Spray Pyrolysis Technique ◽  
Hexagonal Structure ◽  
Zno Films ◽  
Mn Doping ◽  
Mn Concentration

The work deals with the preparation of Zinc Oxide (ZnO) thin films on microscopic glass substrate by spray pyrolysis technique. The systematic study on the influence of Mn doping up to 15% has been performed. The structural studies revealed that pure and doped film has hexagonal structure. In order to reduce the internal strain due to Mn doping, the crystallite size decreases. The atomic force microscopy (AFM) measurement shows the decrease in grain size and roughness with doping. The resistivity curve shows a clear hump corresponding to smaller Mn doping ([Formula: see text]) around [Formula: see text]. This hump was found to reduce with the increase in Mn concentration and for [Formula: see text], beyond which it vanishes completely. This is attributed to critical behavior of resistivity and may be due to the scattering of carriers by magnetic spin fluctuation via exchange interaction. The optical measurement shows the shift in absorption edge of Mn doped ZnO films toward the longer wavelength side. This correlates the reduction in grain size as a function of Mn concentration. The optical bandgap goes down, whereas refractive index increases with dopant concentration.

scholarly journals Structural and Optical Properties of Cobalt-Doped Zinc Oxide Thin Films Prepared By Spray Pyrolysis Technique

2010 ◽  
Vol 7 (1) ◽  
pp. 69-75
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Optical Properties ◽  
Spray Pyrolysis ◽  
Spray Pyrolysis Technique ◽  
Texture Coefficient ◽  
Hexagonal Structure ◽  
Structural And Optical Properties ◽  
Lattice Constants ◽  
Glass Substrates

Undoped and Co-doped zinc oxide (CZO) thin films have been prepared by spray pyrolysis technique using solution of zinc acetate and cobalt chloride. The effect of Co dopants on structural and optical properties has been investigated. The films were found to exhibit maximum transmittance (~90%) and low absorbance. The structural properties of the deposited films were examined by x-ray diffraction (XRD). These films, deposited on glass substrates at (400? C), have a polycrystalline texture with a wurtzite hexagonal structure, and the grain size was decreased with increasing Co concentration, and no change was observed in lattice constants while the optical band gap decreased from (3.18-3.02) eV for direct allowed transition. Other parameters such as Texture Coefficient (Tc), dislocation density (?) and number of crystals (M) were also calculated .

Effect of Molarity of Precursor Solution on Nanocrystalline Zinc Oxide Thin Films

2009 ◽  
Vol 293 ◽  
pp. 99-105 ◽  
Author(s):  
Girjesh Singh ◽  
S.B. Shrivastava ◽  
Deepti Jain ◽  
Swati Pandya ◽  
V. Ganesan
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Solar Cells ◽  
Spray Pyrolysis ◽  
Spray Pyrolysis Technique ◽  
Precursor Solution ◽  
Zno Films ◽  
Scale Production ◽  
Transparent Conducting ◽  
Wide Range

During the last two decades, the use of transparent conducting films of non-stoichiometric and doped metallic oxides for the conversion of solar energy into electrical energy has assumed great significance. A variety of materials, using various deposition techniques, has been tried for this purpose [1-3]. Among these various materials, zinc oxide (ZnO) is one of the prominent oxide semiconductors suitable for photovoltaic applications because of its high electrical conductivity and optical transmittance in the visible region of the solar spectrum [4]. Furthermore, thin films of ZnO have shown good chemical stability against hydrogen plasma, which is of prime importance in a-Si:H-based solar-cell fabrication. Thus, zinc oxide can serve as a good candidate for replacing SnO2 and indium tin oxide (ITO) films in Si:H-based solar cells. One of the outstanding features of ZnO is its large excitonic binding energy, i.e. 60meV, leading to the existence of excitons at room temperature and even at higher temperatures [5-8]. These unique characteristics have generated a wide range of applications of ZnO. For example, gas sensors [9], surface acoustic devices [10], transparent electrodes and solar cells. Many techniques are used for preparing the transparent conducting ZnO films, such as RF sputtering [11], evaporation [12], chemical vapour deposition [13], ion beam sputtering [14] and spray pyrolysis [15–18]. Among these, the spray pyrolysis technique has attracted considerable attention due to its simplicity and large-scale production combined with low-cost fabrication. By using this technique, one can produce large-area coatings without any need for ultra-high vacuum. Thus, the capital cost and the production cost of high-quality zinc oxide semiconductor thin films are lowest among all other techniques. In the present work, we have synthesized ZnO films by using the spray pyrolysis technique. A number of films have been prepared by changing the molarity of the precursor solution. The prepared films have been characterized with regard to their structural, morphological and electrical properties.

Characteristics of Zinc Oxide Film Prepared by Chemical Bath Deposition Method

2014 ◽  
Vol 602-603 ◽  
pp. 871-875
Author(s):  
Yen Pei Fu ◽  
Jian Jhih Chen
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Chemical Bath Deposition ◽  
Deposition Time ◽  
Oxide Films ◽  
Hexagonal Structure ◽  
Zno Films ◽  
Zinc Oxide Film ◽  
Incident Wavelength ◽  
Zinc Oxide Films

In this study, ZnO films, prepared by Chemical Bath Deposition (CBD), are applied as the conductive layers for thin film solar cells. Zinc acetate is used as a source of zinc, and different proportions of ammonia solution are added and well mixed. The growth of zinc oxide films in reaction solutions is taken place at 80°C and then heated to 500°C for one hour. In this study, the different ammonia concentrations and deposition times is controlled. The thin film structure is Hexagonal structure, which is determined by X-ray diffraction spectrometer (XRD) analysis. Scanning electron microscopy (SEM) is used as the observation of surface morphology, the bottom of the film is the interface where the heterogeneous nucleation happens. With the increase of deposition time, there were a few attached zinc oxide particles, which is formed by homogeneous nucleation. According to UV / visible light (UV / Vis) absorption spectrometer transmittance measurements and the relationship between/among the incident wavelength, it can be converted to the energy gaps (Eg), which are about 3.0 to 3.2eV, by using fluorescence spectroscopy analysis. The emission of zinc oxide films has two wavelengths which are located on 510nm and 570nm. According to Based on the all analytic results, the ammonia concentration at 0.05M, and the deposition time is 120 minutes, would obtain the conditions of ZnO films which is more suitable for applications of conductive layer material in thin film solar cell.

Morphological, Structural, Electrical and Optical Properties of Copper-Doped Zinc Oxide Films Deposited by Spray Pyrolysis

2018 ◽  
Vol 930 ◽  
pp. 79-84
Author(s):  
Juliana Simões Chagas Licurgo ◽  
Herval Ramos Paes Junior
Keyword(s):  
Zinc Oxide ◽  
Spray Pyrolysis ◽  
Oxide Films ◽  
Electrical Characterization ◽  
Xrd Analysis ◽  
Band Gap Energy ◽  
Hexagonal Structure ◽  
Material Behavior ◽  
Glass Substrates ◽  
Zinc Oxide Films

In this work, copper-doped zinc oxide films (ZnO:Cu) were deposited by spray pyrolysis on glass substrates. The influence of doping concentration (0-10 at.%) on morphological, structural, optical and electrical properties of the ZnO:Cu films was investigated. Electrical characterization consisted in measuring the variation of electrical conductivity with temperature; they presented a typical semiconductor material behavior. Based on x-ray diffraction (XRD) analysis, it was able to confirm that the films are polycrystalline having a wurtzite hexagonal structure, preferentially oriented in the c-axis (002), and the crystallite size ranged from 41.60 to 50.70 nm. The optical characterization revealed that ZnO:Cu films present band gap energy between 3.18 and 3.27 eV. The films were homogeneous with good adhesion to the substrate. The results indicate the viability of using them in optoelectronic devices.

scholarly journals Transparent ZnO Thin-Film Deposition by Spray Pyrolysis for High-Performance Metal-Oxide Field-Effect Transistors

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3423 ◽  
Author(s):  
Junhee Cho ◽  
Seongkwon Hwang ◽  
Doo-Hyun Ko ◽  
Seungjun Chung
Keyword(s):  
Thin Film ◽  
Metal Oxide ◽  
Spray Pyrolysis ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Spray Pyrolysis Technique ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Zno Films ◽  
Process Conditions

Solution-based metal oxide semiconductors (MOSs) have emerged, with their potential for low-cost and low-temperature processability preserving their intrinsic properties of high optical transparency and high carrier mobility. In particular, MOS field-effect transistors (FETs) using the spray pyrolysis technique have drawn huge attention with the electrical performances compatible with those of vacuum-based FETs. However, further intensive investigations are still desirable, associated with the processing optimization and operational instabilities when compared to other methodologies for depositing thin-film semiconductors. Here, we demonstrate high-performing transparent ZnO FETs using the spray pyrolysis technique, exhibiting a field-effect mobility of ~14.7 cm2 V−1 s−1, an on/off ratio of ~109, and an SS of ~0.49 V/decade. We examine the optical and electrical characteristics of the prepared ZnO films formed by spray pyrolysis via various analysis techniques. The influence of spray process conditions was also studied for realizing high quality ZnO films. Furthermore, we measure and analyze time dependence of the threshold voltage (Vth) shifts and their recovery behaviors under prolonged positive and negative gate bias, which were expected to be attributed to defect creation and charge trapping at or near the interface between channel and insulator, respectively.

Nanostructured ZrO2 Thin Films Deposited by Spray Pyrolysis Techniques for Ammonia Gas Sensing Application

2015 ◽  
Vol 56 ◽  
pp. 120-130 ◽  
Author(s):  
S.B. Deshmukh ◽  
R.H. Bari
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Surface Morphology ◽  
Spray Pyrolysis ◽  
Gas Sensing ◽  
Spray Pyrolysis Technique ◽  
Film Surface ◽  
Ammonia Gas ◽  
Water Solvent ◽  
Average Grain Size

The spray pyrolysis deposition technique has number of advantages to produce advance nanostructured oxide films. The film surface morphology and structure depends on the precursor and doping solution and solvents used with their optimized parameters. The surface to volume ratio is achieved is beneficial to gas sensing. Therefore in this paper we report the nanostructured ZrO2 thin films was prepared using spray pyrolysis technique for ammonia gas sensing. There is various precursors such as Zirconium acetylacetonate, Zirconium nitrate, Zirconium tetra chloride etc. In spite of them, the Zirconium oxychloride octohydrate (0.05 M) was chosen as precursor solution and was prepared by dissolving in pure distilled water (Solvent). The films were deposited on heated glass substrate at 350◦C and were annealed at 500◦C for 1 hrs. It was characterized using XRD, FESEM, and TEM technique to examine crystal structure, surface morphology and microstructure properties. The average crystallite and grain size observed to be nanostructured in nature. The different test target gas performances were tested with various concentrations at different operating temperature. The films sprayed for 20 min with optimized spray parameter were observed to be most sensitive (S=58.5) to NH3 for 500 ppm at 150°C. The film thickness dependence parameters: FWHM (0.02678 radians) for peak 111, Inter-planer distance (d=0.2958 nm), lattice parameters Inter-atomic spacing ( a=0.511 nm), atomic volume(a3= 133Å3 ),micro strain (2.8 to 0.76 x 10-2), crystallite size (4-5nm) average grain size (32nm), dislocation density (1.73 x1015 lines/cm2), texture coefficient (>1), specific surface area(31 m2/g), activation energy and band gap were studied. The sensor shows quick response (4 s) and fast recovery (10 s). Reported results are discussed and interpreted

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