High-entropy alloys (HEAs) have been around since 2004. The breakthroughs in this field led to several potential applications of these alloys as refractory, structural, functional, and biomedical materials. In this work, a short overview on the concept of high-entropy alloys is provided, as well as the theoretical design approach. The special focus of this review concerns one novel class of these alloys: biomedical high-entropy alloys. Here, a literature review on the potential high-entropy alloys for biomedical applications is presented. The characteristics that are required for these alloys to be used in biomedical-oriented applications, namely their mechanical and biocompatibility properties, are discussed and compared to commercially available Ti6Al4V. Different processing routes are also discussed.

Hybrid organic-inorganic perovskite materials have become one of the most studied classes of light-harvesting materials due to their exceptional properties such as high light absorption, long carrier diffusion lengths, bandgap tuning and defect tolerance. Since 2009 that the scientific community has been working on improving the power conversion efficiency (PCE) of perovskite solar cell devices, reaching now an impressive value of 25.5%. Moreover, efficiencies over 18% are often reported by several authors. Since the efficiency goal is almost fulfilled, the scientific community is currently addressing five challenges, with the ultimate objective to make this technology competitive and turn it commercial; these challenges are cost, stability, upscaling, safety and environmental impact.Given the astonishing progresses reached during the past decade and the numerous research groups working to the same goal, it is a matter of time until commercial perovskite solar devices become a reality. In this review work, the most recent achievements regarding this purpose are put together and compared, so as to suggest the most suitable perovskite solar fabrication processes and materials to produce commercial devices.

The increasing demand for solar energy has led researchers worldwide to develop new photovoltaic technologies. Among these, perovskite materials are one of the most promising candidates, with a performance evolution unparalleled in the photovoltaic field. However, this thin-film technology is not yet available at a commercial level, mainly due to upscaling issues. This work studied the best design options for upscaling single cells into modules by minimizing electrical losses in the device substrates. The software LAOSS was used to test and optimize different substrate sizes and designs and to predict several performance outcomes from experimentally fabricated single cells. The results showed that it is possible to retain most of the energy production when upscaling from a single cell to a module if the appropriate design for an efficient monolithic device is used. The width of the interconnection zone also plays an important role in device performance and must be carefully optimized during module design. It then demonstrates the importance of having precise laser tools, which are essential for narrow and smooth scribes, and how useful simulation software can be, which, combined with experimental developments, will facilitate efficient module fabrication, aiming to establish it as a feasible and marketable resource.