6 research outputs found

    Effect of the deposition time on optical and electrical properties of semiconductor ZnS thin films prepared by chemical bath deposition

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    Semiconductor ZnS thin films have been deposited by a chemical bath deposition (CBD) on a glass substrate at 80 °C with different deposition time (4, 6 and 8 h). The films have been further studied in order to determine the change in optical and electrical properties as a function of deposition time. The film thicknesses have been calculated between 210–1375 nm by using gravimetrical analysis. The optical properties of ZnS thin films have been determined by transmittance (%T) and absorbance (A) measurements by UV-Vis spectroscopy operated wavelength range between 300 and 1100 nm at room temperature. The optical transmittance values of ZnS thin films in the visible region of the electromagnetic spectrum have been found to be between 51–90%. The calculations indicate that the refractive index (n) in the visible region is between 1.40 and 2.45. The optical band gaps (Eg) of thin films have been calculated between 3.61–3.88 eV while the band edge sharpness values (B) are varied between 6.95×109–8.96×1010 eV/cm2. The specific resistivity values (ρ) of the films are found to be between 1.08×105–1.01×106 Ω·cm and exhibit an n-type conductivity by Hall measurement

    Acceptor formation in Mg-doped, indium-rich Ga x In1−xN: evidence for p-type conductivity

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    We report on the Mg-doped, indium-rich GaxIn1-xN (x 150 K, is determined by the longitudinal-optical phonon scattering together with the thermal regeneration of non-equilibrium minority carriers from traps with an average depth of 103 +/- 15 meV. This value is close to the Mg binding energy in GaInN. The complementary measurements of transient photoluminescence at liquid He temperatures give the e-A0 binding energy of approximately 100 meV. Furthermore, Hall measurements in the Mg-doped material also indicate an activated behaviour with an acceptor binding energy of 108 +/- 20 meV

    Structural and Optical Properties of Diluted Magnetic Ga1−xMnxAs–AlAs Quantum Wells Grown on High-Index GaAs Planes

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    We report on the structural and optical properties of Ga₁₋á”Ș Mn á”Ș As-AlAs quantum wells (QWs) with χ=0.1% grown by molecular beam epitaxy (MBE) on semi-insulating GaAs substrates with orientations (100), (110), (311)B and (411)B. Atomic force microscopy (AFM), X-ray diffraction (XRD) and photoluminescence (PL) techniques were used to investigate these QWs. AFM results have evidenced the formation of Mn-induced islands, which are randomly distributed on the surface. These islands tend to segregate for samples grown on (110) and (411)B planes, while no clear segregation was observed for samples grown on (100) and (311)B orientations. Results show that the PL line width increases with Mn segregation. XRD measurements were used to determine 2Ξ,d and cell parameters

    Structural and electronic properties of SnO2

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    WOS: 000324523500010Highly transparent polycrystalline thin film of SnO2 (tin dioxide) was deposited using a simple and low cost spray pyrolysis method. The film was prepared from an aqueous solution of tin tetrachloride (stannic chloride) onto glass substrates at 400 degrees C. A range of diagnostic techniques including X-ray diffraction (XRD), UV-visible absorption, atomic force microscopy (AFM), scanning electron microscopy (SEM), and synchrotron-based X-ray photoelectron spectroscopy (XPS) were used to investigate structural, optical, and electronic properties of the resulting film. Deposited film was found to be polycrystalline. A mixture of SnO and SnO2 phases was observed. The average crystallite size of similar to 21.3 nm for SnO2 was calculated by Rietveld method using XRD data. The oxidation states of the SnO2 thin film were confirmed by the shape analysis of corresponding XPS O 1s, Sn 3d, and Sn 4d peaks using the decomposition procedure. The analysis of the XPS core level peaks showed that the chemical component is non-stoichiometric and the ratio of oxygen to tin (O/Sn) is 1.85 which is slightly under stoichiometry. (c) 2013 Elsevier B.V. All rights reserved.Office of Science, Office of Basic Energy Sciences, of the US Department of Energy [DE-AC02-05CH11231]The authors are grateful to the Advanced Light Source, Berkeley, California USA for providing synchrotron-based XPS facility. The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the US Department of Energy under Contract No. DE-AC02-05CH11231

    Acceptor formation in Mg-doped, indium-rich GaxIn1-xN: evidence for p-type conductivity

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    We report on the Mg-doped, indium-rich Ga (x) In1-x N (x 150 K, is determined by the longitudinal-optical phonon scattering together with the thermal regeneration of non-equilibrium minority carriers from traps with an average depth of 103 +/- 15 meV. This value is close to the Mg binding energy in GaInN. The complementary measurements of transient photoluminescence at liquid He temperatures give the e-A(0) binding energy of approximately 100 meV. Furthermore, Hall measurements in the Mg-doped material also indicate an activated behaviour with an acceptor binding energy of 108 +/- 20 meV
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