Among thin-film photovoltaic technology, cadmium telluride (CdTe) has achieved a truly impressive development that can commercially compete with silicon, which is still the king of the market. Solar cells made on a laboratory scale have reached efficiencies close to 22%, while modules made with fully automated in-line machines show efficiencies above 18%. This success represents the result of over 40 years of research, which led to effective and consolidated production processes. Based on a large literature survey on photovoltaics and on the results of research developed in our laboratories, we present the fabrication processes of both CdTe polycrystalline thin-film solar cells and photovoltaic modules. The most common substrates, the constituent layers, their interaction, the interfaces and the different “tricks” necessary to obtain highly efficient devices will be analyzed. A realistic industrial production process will be analytically described. Moreover, environmental aspects, end-of-life recycling and the life cycle assessment of CdTe-based modules will be deepened and discussed.

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Sb2Se3 is a typical V2VI3 binary chalcogenide compound characterized by a single crystalline phase and a fixed composition. Sb2Se3 displays a narrow energy gap ranging from 1.1 to 1.3 eV, which are quite optimal values for single-junction solar cells. Earth-abundant and non-toxic components make this material a good candidate for low-cost thin-film solar cells. In substrate configuration, a world record efficiency of 9.2% was recently obtained. Sb2Se3 thin films exhibit an accentuated predisposition to form (Sb4Se6)n ribbons along the [001] direction. This anisotropy heavily influences the charge transport of the photogenerated carriers. In this work, structural characterization of the Sb2Se3 films showed that the crystalline quality and preferential orientation are strongly dependent on the window layer used. To better understand the growth mechanism, Sb2Se3 thin films were deposited by close-spaced sublimation on five different window layers, such as CdS, CdS:F, CdSe, As2S3, and ZnCdS. Sb2Se3-based solar cells, realized in superstrate configuration on these different substrates, evidently demonstrate the influence of the Sb2Se3 preferential orientation on the photovoltaic parameters.