Transparent and conducting SnO 2 thin film has been produced on quartz substrate using rapid thermal oxidation of pure Sn in air at different oxidation temperature and oxidation time. The transmittance T in the visible and NIR was investigated, the allowed direct energy gap was determined to be 3.18 eV at optimum condition of 600° and 90 s. The dependence of the resistivity on the film thickness and oxidation time has been studied. The optimum thickness of high transmittance and lowest resistivity is about 150 nm for SnO 2 were ρ = 2 × 10-2Ω cm and T = 88%.

Palladium, Indium and Silver-doped SnO 2 thin film was deposited by chemical spray pyrolysis on ITO and porous silicon substrates to be a fast MgSO 4 Á7H 2 O amperometric biosensor. The prepared SnO 2 films were doped by dipping in palladium chloride PdCl 2 , indium chloride, InCl 3 and silver nitrides AgNO 3 dissolved in ethanol C 2 H 5 OH. The structural and optical properties of the prepared films were studied. The sensitivity behaviors of SnO 2 , SnO 2 : Pd, SnO 2 : In and SnO 2 : Ag based on the amperometric biosensor to MgSO 4 Á7H 2 O salts were investigated at room temperature with different doping.

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Near-ideal n- SnO 2/n- Si heterojunction band edge lineup has been investigated with aid of I–V and C–V measurements. The heterojunction was manufactured by rapid thermal oxidation of Sn metal films prepared by thermal evaporation technique on monocrystalline n-type silicon. The experimental data of the conduction band offset ΔEc and valence band offset ΔEc were compared with theoretical values. The band offset ΔEc = 0.55 eV and ΔEv = 1.8 eV obtained at 300 K. The energy band diagram of n- SnO 2/n- Si HJ was constructed. C–V measurements depict that the junction was an abrupt type and the built-in voltage was determined from 1/C2–V plot.

The thermal evaporation system type (Edwards) has been used to evaporate high purity (99.9 %) silver on glass, n-and p-type silicon and porous silicon substrates at room temperature under low pressure (about 10 -6 torr) for different thickness (50, 75, 100, 125 and 150 nm). Using a rapid thermal oxidation of Ag film at oxidation temperature 350°C and different oxidation times, Ag 2 O thin film was prepared. The structural properties of Ag 2 O film were investigated and compared with other published results. The structural investigation showed that the films formed at thickness 100 nm showed (111) strong reflection along with weak reflections of (101) corresponding to the growth of single phase Ag 2 O with cubic structure. Dark and illuminated I-V of p-Ag 2 O/p-Si, p-Ag 2 O/n-Si, Al/p-PSi/Al, Al/n-PSi/Al, p-Ag 2 O/p-PSi/c-Si and p-Ag 2 O/n-PSi/c-Si heterojunction were investigated, discussed and prepared at optimum condition (oxidation temperature 350°C and 90 s oxidation time with thickness 100 nm). Ohmic contacts were fabricated by evaporating 99.999 purity silver wires for back and aluminum wires for front contact, respectively.