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The study results of thin semiconductor films CdxPb1-xS sensory properties in relation to the nitrogen dioxide content in the air are presented. The effect of the cadmium acetate CdAc2 concentration salt in a reaction mixture on the phase composition, crystal structure, and morphology of the solid solution CdxPb1−xS synthesized films has been established using X-ray diffraction and scanning electron microscopy methods. It has been revealed that sensory-based on deposited films of different composition have distinction interaction with nitrogen dioxide. The threshold for determination is the concentration of NO2 in the air of about 0.08 mg/m3. The spontaneous relaxation of thin films after contact with nitrogen dioxide makes it possible of creating reusable chemical sensors based on CdxPb1−xS films characterized by relatively low threshold concentrations of nitrogen dioxide detection. [ABSTRACT FROM AUTHOR]

Solid solution CdxPb1−xS films were synthesized by chemical bath deposition method from aqueous solutions of lead acetate and cadmium salts with different anionic component concentrations up to C[CdAn] = 0.06 mol/L in the presence of thiourea and complexing agents. According to X-ray structural analysis, introducing cadmium salts resulted in a decrease in the lattice parameter. The lowest value of the lattice parameter is observed for salts containing oxygen in the anionic component. The cadmium content of these films is estimated to be x = 0.24. Analysis of the absorption spectra of CdxPb1−xS films in the near IR range indicates the increase in the bandgap width of lead sulfide when cadmium is added. When the anion of the cadmium salt changes from iodide-ion to acetate-ion, the bandgap increases from 0.62 to 0.77 eV. The larger bandgap is consistent with the greater cadmium concentration in the films determined from the X-ray structural analysis and indicates the beneficial effect of oxygen on the introduction of cadmium into the lead sulfide lattice. [ABSTRACT FROM AUTHOR]

Polycrystalline PbS films doped with cadmium and iodine ions were produced by CBD with thiocarbamide in the presence of NH4I and CdI2 on glass substrates, the maximum content of impurity ions Cd2+ and I− amounted to 2.76±0.04 at% and 1.80±0.09 at%, respectively. SEM study showed that the faceting of crystallites forming the film layer disappeared and their average sizes decreased from 250 to 90 nm with the introduction of cadmium and iodine into the reaction bath. X-ray diffraction detected the increase in the crystal lattice period of a lead sulfide film from 0.5936(8) to 0.5938(0) nm that indicates the incorporation of cadmium and iodine into the cubic B1 structure (space group Fm3̄m), contributing to the growth of strains. The bandgap Eg of the doped layers of lead sulfide increases slightly from 0.83±0.02 to 1.00±0.02 eV. [ABSTRACT FROM AUTHOR]

Functional films of supersaturated substitutional CdxPb1-xS solid solutions (0 < x < 0.24) were produced by the chemical bath chemical deposition method on the quartz glass. The cadmium content in the solid solution was determined by X-ray diffraction. The size of crystallites forming the film, the degree of their texture and the microstress sizes were also estimated. The dislocation density in the synthesized films was calculated by analyzing the anisotropy of microstresses. By the investigation of absorption spectra, the bandgap Eg of CdxPb1-xS solid solutions depending on the cadmium content (x) was determined. The variation of the bandgap of CdxPb1-xS provides the possibility of the effective control of photoelectric and optical characteristics of the deposited films in the spectral range of 0.4-3.0 μm. [ABSTRACT FROM AUTHOR]