PbxSn(1−x)S (0.05<x<0.20) thin films with the thickness of 2μm were deposited on glass substrates using hot wall vacuum deposition method at the vacuum pressure of 5×10−4Pa, wall temperature of 600°С, substrate temperature of 300°С and subsequently annealed at 450°C in vacuum at 5×10−4Pa. The microstructure and optical properties of the as-deposited and annealed films were examined in relation to the film composition. The explanations of lattice parameter deviations from the bulk crystals for both as-deposited and annealed PbxSn(1−x)S thin films are discussed. The PbxSn(1−x)S thin films exhibit a preferred orientation around the [111] direction. The annealing decreases the film microstrain values and increases the grain size and the degree of preferred orientation. Thermal probe measurements showed the sulfur-deficient films to be p-type and the sulfur-rich films to be n-type. The PbxSn(1−x)S films exhibit direct allowed transitions with energy band gap Eg(d) increasing with the increase of Pb mole fraction. The Eg(d) values for as-deposited films range from 0.95 to 0.98eV and for annealed films they variy from 0.90 to 0.94eV.

Tin monosulfide SnS raises an interest as a promising material for photovoltaics. The influence of the substrate material on the microstructure and optical properties of SnS thin films with [111] texture obtained by hot wall vacuum deposition on glass, molybdenum and indium tin oxide substrates is reported. The lattice parameters for layers grown on different substrates were determined by X-ray diffraction and their deviations from the data reported in the literature for single α-SnS crystals were discussed. The change in the degree of preferred orientation of the films depending on the substrate material is observed. The direct nature of the optical transitions with the optical band gap of 1.15±0.01eV is reported.

The influence of thermal treatment on the microstructure and electrical and optical properties of SnS films obtained by the “hot-wall” method has been investigated. It has been established that the thermal treatment does not lead to the formation of foreign phases in the film composition. The average film roughness after the thermal treatment increases from 10 to 20 nm. Resistivity after the thermal treatment decreases from 230 to 100 Ωcm (T = 300 K), while the temperature coefficient of thermopower increases from 40 to 330 μV K−1. The band gap is 1.46 eV. The adsorption edge is not displaced after the thermal treatment.

In this paper, we present a comparative research of the nanoscale modification of the surface morphology of polycrystalline SnS films on glass substrates with two different preferred growth orientations processed in inductively coupled argon plasma. We report a new effect of polycrystalline SnS film surface smoothing during plasma treatment, which can be advantageous for the fabrication of multilayer solar cell devices with SnS absorption layers.

Tin sulfide (SnS) is one of the most promising materials for photovoltaics. Here we report on the preparation as well as chemical, structural and physical characterization of the Mo/p-SnS/n-CdS/ZnO heterojunctions. The SnS thin films were grown by hot wall deposition method on the Mo-coated glass substrates at 270–350°C. The crystal structure and elemental composition were examined by X-ray diffraction and Auger electron spectroscopy methods. The CdS buffer layers were deposited onto the SnS films by chemical bath deposition. The ZnO window layers were deposited by a two step radio frequency magnetron sputtering, resulting in a ZnO bilayer structure: the first layer consists of undoped i-ZnO and the second of Al-doped n-ZnO. The best junctions have an open circuit voltage of 132mV, a short circuit current density of 3.6mA/cm2, a fill-factor of 0.29 and efficiency up to 0.5%.

Thin Pb x Sn 1 − x S films are obtained by the “hot-wall” method at substrate temperatures of 210–330°C. The microstructure, composition, morphology, and electrical characteristics of films are investigated. On the basis of the obtained films, photosensitive In/ p -Pb x Sn 1 − x S Schottky barriers are fabricated for the first time. The photosensivity spectra of these structures are investigated, and the character of interband transitions and the band-gap values are determined from them. The conclusion is drawn that Pb x Sn 1 − x S thin polycrystalline films may be used in solar-energy converters.

The dependence of the microstructure and optical properties of SnS thin films fabricated by hot wall deposition onto glass substrates on the deposition conditions is studied. Phase and elemental composition, surface morphology, and transmission spectra of the obtained films are investigated within the wavelength range 400–2500 nm. The single-phase films feature near-stoichiometric elemental composition and a high degree of preferential orientation in the (040) plane. The optical band gap for direct transitions is 1.07–1.27 eV, depending on film thickness.

The PbxSn1‐xS (x = 0 – 0.25) thin films were prepared on glass substrates by hot wall vacuum deposition. The films were polycrystalline monophase in nature and had orthorhombic crystal structure. The thickness of the films was about 2‐3 μm. The temperature dependences of the conductivity were measured in the temperature range from 150 to 420 K. The films revealed p‐type of conductivity. The Seebeck coefficient and conductivity values of the films was in the range of α = 6 – 360 μV/K and σ = 4.8×10‐5 – 1.5×10‐2 Ω‐1·cm‐1, respectively, at room temperature depending on concentration of the lead in the films. The lead atoms created the substitution defects PbSn in the crystal lattice of the PbxSn1‐xS. These defects formed the donor energy levels in the band gap. The activation energy of the films increased in the range ΔEa = 0.121 – 0.283 eV with increasing of the lead concentration. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Thin films of lead tin sulphide PbSnS2 were deposited on glass substrates at 100 degrees C at vacuum pressure of 3x 10(-6) mbar using a thermal evaporation method. Scanning electron microscopy (SEM) and X-ray characterization revealed that thin films were monophase and polycrystalline. The average particle size was approximately 28 nm. Absorption coefficient of PbSnS2 thin films (similar to 10(5) cm(-1)) was found from transmission optical spectroscopy measurements. Its fundamental absorption edge is shown to be 1.65 eV with direct allowed transition recommended for photovoltaic application. Thermoelectric measurements showed the materials to be p-type in nature. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

the high absorption coefficient of approximately 104 - 105 cm-1 in a wide spectral region, and compared to pure CuInSe2 the CIZS system gives the advantage to change the band gap from 1.02 eV (CuInSe2) to 2.67 eV (ZnSe) (5). This suggests that they can be used in thin film solar cells as absorbers as well a wide-gap window layer. The Cu/(In+Zn) ratio of the CIZS layers is the crucial parameter for the physical properties of the semiconductor material as well for the solar cell applications (6). Optical methods such as photoluminescence (PL) and absorption spectroscopy are powerful tools for the characterization of semiconductor mate- rials and thin film solar cells (7). The aim of this work is the investigation of the optical properties of CIZS films with the zinc concentration in the range of 0.0 - 8.0 at. %. 2. Experimental Cu(In,Zn)Se2 thin films were prepared onto 7.0×2.5 cm 2 soda lime glass substrates with and without 0.5 - 1.0 μm thick molybdenum layers, which were dc sputtered. The ZnSe/(Cu+In) precursors were prepared by the standard thermal evaporation in vacuum of 5⋅10-6 Torr at the substrate temperature Ts = 100°С. A single rotatable crucible in this system permitted the sequential deposition of ZnSe, In and Cu in any desired sequence and thickness without breaking the vacuum. The thickness of the respective layers was varied to obtain the required ZnSe/(Cu+In) atomic ratio. The Cu/In atomic ratio in the precursors was varied in limits of 0.88÷1.10 and the total thickness was 0.6 - 1.0 μm. The structures were then selenized by diffusion of elemental selenium from solid state sources into the alloy films in nitrogen flow using two-step annealing temperature profile. The process was performed in an electrical furnace, which allowed fast heating of the samples. The selenization system consisted of a special container for precursors and pots to accommodate Se material. Spacing between samples was maintained at 4.0 mm to ensure energetic over-pressure of selenium