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Sb2S3 powder was successfully synthesized by solid state reaction technique using high-purity elemental antimony and sulfur. Sb2S3 thin films were deposited on unheated glass substrates by one step thermal evaporation and annealed under vacuum atmosphere for 2 hours at different temperatures 150, 200 and 250 °C. Different characterization techniques were used to better understand the behavior of the Sb2S3 material. X-ray diffraction (XRD) and Raman spectroscopy confirmed the formation of pure Sb2S3 powder with lattice parameters a = 11.07 Å, b = 11.08 Å and c = 3.81 Å. The effect of vacuum annealing temperature on the properties of the films was studied. XRD analysis revealed that as-deposited and annealed films at 150ºC were amorphous in nature whereas those annealed at T ≥ 200°C were polycrystalline with a preferred orientation along (201) plane. The crystallite size of the polycrystalline films showed a decrease from 75.8 to 62.9 nm with the increase of the annealing temperature from 200 to 250 °C. The Raman analysis showed several peaks corresponding to the stibnite Sb2S3 phase. The surface morphology of the films was examined by atomic force microscopy (AFM). The surface roughness decreases slightly as the transformation from the amorphous to the crystalline phase occurs. The chemical compositions of Sb2S3 films were analyzed by energy dispersive X-ray spectroscopy (EDS), revealing that all films were Sb-rich. The optical parameters were estimated from the transmittance and reflectance spectra recorded by UV-Vis spectroscopy. A reduction in the direct band gap energy from 2.12 to 1.70 eV with the increase of annealing temperature was also found.

In order to study the Zinc Tin Oxide (ZTO) as an alternative buffer layer to replace CdS in thin films solar cells, we synthesized the (Zn,Sn)O material using the vacuum thermal evaporation of the metal compounds, Tin and Zinc, followed by annealing treatments. The obtained samples were divided into two groups according to the amount of Tin used during the thermal evaporation while the amount of Zinc remains invariant. The first group of ZTO thin films was made using a Tin amount of 0.312 g and annealed in air at different temperatures (samples A). The second group was made using a less amount of Tin (0.156 g) (samples B). Part of these samples were annealed in air atmosphere (samples B1) whereas the other sample was annealed under vacuum then annealed in air (sample B2). The annealing process was mainly dedicated to the oxidation treatment of Sn/Zn metallic bilayers but it also plays an important role to improve the crystallinity of the as-deposited films. The structural, optical and electrical properties of the prepared films were characterized using X-ray diffraction, UV-VIS-NIR spectrophotometry and impedance spectroscopy, respectively. We have succeeded to obtain a stable cubic spinel structure of Zn 2 SnO 4 phase (sample B2). This thin film showed interesting properties such as a direct band gap energy of value of 3.20 eV, a high optical transmission of 80% and a n-type electrical conductivity.