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Evolution of the morphology, composition, structural characteristics (lattice constant, microstrains, texturing), and optical and photoelectric properties of PbS films produced by chemical deposition in the presence of ammonium iodide and chromium (III) chloride at concentrations of up to 0.02 M is studied. According to the data of elemental analysis by energy-dispersive X-ray spectroscopy, the Cr content in PbS films nonmonotonically depends on the CrCl3 concentration, and the highest content is 1.08 at %. The size distribution of particles is monomodal, and the average size of particles forming the films varies from ~100 to ~225 nm at a nanoparticle content of 2–6%. The introduction of NH4I and CrCl3 into the reactor preserves the B1 cubic structure of PbS and yields an increase in the band gap Eg by 0.16–0.20 eV, a decrease in the dark resistance Rd, and an increase in the voltage sensitivity Us. The dependences of Eg and Us on the chromium-salt concentration in the reaction bath are of extreme character, with a maximum at 0.016 M of CrCl3, which is due to the nonmonotonic incorporation of chromium into the PbS lattice. The results of studies of the current–voltage characteristics of PbS(I) and PbS(I, Cr) thin-film layers are in good agreement with the data on the structural, optical, and photosensitivity properties. [ABSTRACT FROM AUTHOR]

The possibility of forming thin-film two-phase compositions CdxPb1-xS/Cd1−δS using chemical bath deposition from aqueous media with adding various cadmium salts has been demonstrated. The crystal structure, chemical composition, morphology, and the band gap were studied by the X-ray diffraction, scanning electron microscopy, elemental analysis, Auger and Raman spectroscopy, and diffuse reflectance measurements. The formation of a CdxPb1−xS/Cd1−δS substitutional solid solution phase in well-faceted crystallites on the substrate of an X-ray amorphous CdS phase was experimentally shown. The observed difference in the composition of the films deposited with adding different cadmium salts is the result of the effect of the nucleophilicity of the anionic component of these salts on the kinetics of thiourea decomposition. The results demonstrate the possibility of forming thin-film two-phase compositions or heterostructures on the base of cadmium and lead sulfides in one technological stage using chemical bath deposition, which can be important for the creation of solar cells. [ABSTRACT FROM AUTHOR]

Polycrystalline lead-sulfide (PbS) films doped with calcium are synthesized on sitall and glass substrates by chemical bath deposition with the use of thiocarbamide and a CaCl2 additive at concentrations of up to 5 mM. Introduction of the CaCl2 additive into the reaction solution greatly prolongs the induction period of the process of synthesis. The thicknesses of the PbS and PbS(Ca) films are, correspondingly, 200 and 150 nm at an average crystallite dimension of ~100 nm. The maximum calcium content in the films is 0.06 at % for layers on sitall substrates and 0.11 at % for layers on glass substrates. Doping with calcium does not influence the crystal structure of lead sulfide (the cubic B1 structure, space group Fm3 ) but brings about an increase in the crystal-lattice period from a = 0.59343(2) nm to a = 0.59413(1) nm, an increase in microstrains, and partial ordering of the crystallites forming the film. Upon the introduction of calcium, the band gap decreases from Eg = 0.40 eV at 295 K (0.38 eV at 90 K) to Eg = 0.38 eV (0.37 eV). The introduction of up to 5 mM of CaCl2 into the reaction mixture increases the voltage–power sensitivity of the films by a factor of ~1.7, which is attributed to oxygen-containing compounds formed in the films as a result of the increase in the induction period of the process of synthesis. [ABSTRACT FROM AUTHOR]

The phase composition, microstructure, and volume distribution of the dispersed lead sulfide phase in the matrix of the synthesized organomineral composite sorbent KU-2×8−PbS were studied. The cation exchanger granules are coated with a virtually continuous layer of lead sulfide up to 1.8-2.5 μm thick. In the volume of cation exchanger granules, the PbS phase forms discrete spherical particles with the mean diameter of 90-100 nm. Experiments on competing sorption of Cu(II) and Zn(II) from nitrate solutions revealed high selectivity of the sorbent to copper. Zinc concentrations of up to 0.004 mM do not noticeably affect the copper sorption, ensuring the possibility of separating the metals in the sorption step. [ABSTRACT FROM AUTHOR]

A hydrochloric acid solution of hydrogen peroxide was suggested for etching lead sulfide films. The solubility of lead sulfide in relation to the hydrochloric acid concentration in the etching solution was calculated using thermodynamic analysis, taking into account the stability of lead complex species. The kinetics of hydrogen peroxide decomposition in the hydrochloric acid solution was studied, and the formal rate equation of the process was constructed. [ABSTRACT FROM AUTHOR]

Thin nanostructured films of lead sulfide-based CdxPb1-xS solid solutions, strongly supersaturated with respect to the substituting component, were prepared by hydrochemical deposition from ammonia-citrate, ethylenediamine-citrate, and ethylenediamine reaction mixtures onto glass-ceramic substrates. The structure, composition, and morphology of the resulting films were examined. An interesting feature of the synthesis was revealed, a distinct correlation between the linear dimensions of the crystallites constituting the films and the cadmium sulfide content therein: the higher cadmium sulfide content, the smaller were the crystallites. [ABSTRACT FROM AUTHOR]

Semiconductor and photoelectric characteristics of films of solid solutions of PbSeS obtained through combined hydrochemical deposition of lead sulfide and selenide from a citrate-ammonia reaction bath by a mixture of thio- and selenocarbamide have been investigated. The effect of thermal treatment in air at (633-668) K on the composition, structure, morphology, and photosensitive characteristics of PbSeS films has been investigated. The synthesis conditions and composition of PbSeS films providing the maximum photoresponse level have been revealed. [ABSTRACT FROM AUTHOR]

We propose a technique for wet-chemical codeposition of lead sulfide and selenide using thiourea and selenourea to form films of PbSeS substitutional solid solutions. The synthesized nanocrystalline layers with NaCl (B1) structure simultaneously contain both PbS-based and PbSe-based PbSeS solid solutions (0 < y < 0.9). [ABSTRACT FROM AUTHOR]

The optical and dielectric characteristics of hydrochemically deposited films of lead sulfide (PbS) and supersaturated substitutional solid solutions of the PbS-ZnS system have been studied by the ellipsometry techniques. It is established that the formation of solid solutions leads to an increase in the refractive index and a decrease in the imaginary part of the complex dielectric constant as compared to those of pure PbS films. An increase in the content of ZnS in the solid solution us accompanied by a significant decrease in the dielectric loss tangent. [ABSTRACT FROM AUTHOR]

Polycrystalline lead-sulfide (PbS) films doped with calcium are synthesized on sitall and glass substrates by chemical bath deposition with the use of thiocarbamide and a CaCl2 additive at concentrations of up to 5 mM. Introduction of the CaCl2 additive into the reaction solution greatly prolongs the induction period of the process of synthesis. The thicknesses of the PbS and PbS(Ca) films are, correspondingly, 200 and 150 nm at an average crystallite dimension of ~100 nm. The maximum calcium content in the films is 0.06 at % for layers on sitall substrates and 0.11 at % for layers on glass substrates. Doping with calcium does not influence the crystal structure of lead sulfide (the cubic B1 structure, space group Fm3 ) but brings about an increase in the crystal-lattice period from a = 0.59343(2) nm to a = 0.59413(1) nm, an increase in microstrains, and partial ordering of the crystallites forming the film. Upon the introduction of calcium, the band gap decreases from Eg = 0.40 eV at 295 K (0.38 eV at 90 K) to Eg = 0.38 eV (0.37 eV). The introduction of up to 5 mM of CaCl2 into the reaction mixture increases the voltage–power sensitivity of the films by a factor of ~1.7, which is attributed to oxygen-containing compounds formed in the films as a result of the increase in the induction period of the process of synthesis. [ABSTRACT FROM AUTHOR]