http://eprints.iisc.ernet.in/18194/1/Structural.pdf

Structural and electrical studies on highly conducting spray deposited fluorine and antimony doped SnO2 thin films from SnCl2 precursor

Tin oxide films doped with oxygen vacancies, F, Sb, or Mo were made by reactive rf magnetron sputtering of Sn, Sn‐Sb, or Sn‐Mo in Ar+O2(+CF4) onto glass heated to a temperature up to 530 °C. Electrical dc resistivity, mobility, free‐electron density, spectral optical properties, and microstructure were investigated as a function of sputtering parameters. Optimized deposition parameters gave SnOx:(Sb,F) films with high luminous transmittance, low luminous absorptance, high infrared reflectance, and dc resistivity down to 9.1×10−4 Ω cm. Refractive index n and extinction coefficient k were evaluated from spectrophotometric transmittance. In the luminous range, the films had 1.90<n<2.0 and k of the order of 10−2. Hall‐effect measurements showed n‐type conduction with electron densities in the 1020–1021 cm−3 range. Band‐gap broadening from 4.06 to 4.45 eV was observed with increasing electron density. X‐ray diffractometry and transmission electron microscopy showed that the structure factor of the films depend...

Optical and electrical properties of radio frequency sputtered tin oxide films doped with oxygen vacancies, F, Sb, or Mo

Scattering mechanisms of charge carriers in Transparent Conducting Oxide (TCO) films have been analyzed theoretically. For the degenerate polycrystalline TCO films with relatively large crystallite sizes and high carrier concentrations (higher than 5 × 1018 cm−3), the depletion layers between crystallites are very thin compared to the crystallite sizes, and the grain boundary scattering on electrical carriers makes a small contribution to limit the mobility of the films. Instead of thermionic emission current, a tunneling current dominates the electron transport over grain boundaries. The Petritz model which is based on thermionic emission and extensively quoted in literature should not be applicable. The main scattering mechanisms for the TCO films are ionized impurity scattering in the low-temperature range and lattice vibration scattering in the high-temperature range. The ionized impurity scattering mobility is independent of temperature and the mobility due to thermal lattice vibration scattering is inversely proportional to the temperature. The results obtained from Hall measurements on our ZnO, ITO, SnO2 and SnO2:F films prepared with various methods supports the analysis.

Scattering mechanisms of charge carriers in transparent conducting oxide films

A study on low cost-high conducting fluorine and antimony-doped tin oxide thin films

Correlation between structural and electrical properties of sprayed tin oxide films with and without fluorine doping

Tin oxide films were deposited by chemical vapor deposition on borosilicate and fused silica substrates using dibutyltin diacetate (DBTD) as tin feedstock and SbC/sub 5/ or CC/sub 3/-CF/sub 3/ as dopants. The film growth rate was measured as a function of dopant/DBTD ratio, temperature, and film thickness. Scanning electron microscopy and x-ray diffraction spectra of the films were used to determine the grain sizes and the preferential orientations of the crystallites in the film as a function of film thickness. Optical and electrical properties were measured. A model is proposed to elucidate the variation of transport properties of doped SnO/sub 2/ as a function of film thickness. It could b shown with this model that the thickness dependence of the conductivity of doped SnO/sub 2/:Sb and SnO/sub 2/:F films could be analyzed in terms of carrier concentration taking into consideration deep-level compensation. The number of carriers is decreased by electron trapping at Sb(III) or Sn(II) surface states when antimony or fluorine are used as dopant, respectively. The model based on results of the literature related to a single crystal with (110) orientation is extended in this work to other crystallite orientations. The present analysis indicates that deep levels appear onlymore » on the grain boundary surfaces with (110), (211), and (301) orientations, and not on the (200) and (400) ones. The concentration of free carriers can be calculated on the basis of x-ray diffraction spectra indicating an estimate of the relative fraction of the crystallites with each orientation as a function of the film thickness. The conductivities of the films can be computed using this model and taking a single value for the electron mobility of 19 cm/sup 2/ (V-s)/sup -1/ for all film thickness and a total donor concentration of 2 x 10/sup 20/ cm/sup -3/. All the obtained experimental data can be accounted for exclusively on the basis of film-thickness dependent carrier concentration.« less

Thickness Dependence of Transport Properties of Doped Polycrystalline Tin Oxide Films

Confirmation de l'epitaxie par diffraction RX et observation au microscope electronique a balayage de l'orientation et de la forme des piqures d'attaque. Effet du flux d'hydrogene entre source et support et de la temperature de transport sur la croissance des couches

J. I. Dickson

Papers

Thickness Dependence of Transport Properties of Doped Polycrystalline Tin Oxide Films

Epitaxy of GaAs by the Close‐Spaced Vapor Transport Technique

Thermodynamic equilibrium displacement controlled epitaxial growth of GaAs

Epitaxy of GaAs by the Close-Spaced Vapor Transport (CSVT) Technique.