Editor-in-Chief Sean Shaheen summarizes the state of photovoltaics.

This report provides a snapshot of emerging photovoltaic (PV) technologies. It consists of concise contributions from experts in a wide range of fields including silicon, thin film, III-V, perovskite, organic, and dye-sensitized PVs. Strategies for exceeding the detailed balance limit and for light managing are presented, followed by a section detailing key applications and commercialization pathways. A section on sustainability then discusses the need for minimization of the environmental footprint in PV manufacturing and recycling. The report concludes with a perspective based on broad survey questions presented to the contributing authors regarding the needs and future evolution of PV.

Improving the TEM₀₀-mode laser efficiency is one of the main goals in solar laser research, motivated by the significant importance these high-quality beams hold for fields, such as materials processing. A seven-rod concept was designed to enhance the TEM₀₀-mode solar laser efficiency through the adoption of Ce:Nd:YAG active media. Collection and concentration of solar rays were conducted by seven Fresnel lenses, assisted by six folding mirrors. The laser head was composed of seven aspheric lenses, a hexagonal window and seven grooved Ce:Nd:YAG rods, which were end-side-pumped. A total TEM₀₀-mode laser power of 172.59 W was numerically achieved, corresponding to a 34.52 W / m² collection efficiency and a 3.63% solar-to-laser power conversion efficiency. These efficiency values were 1.51 and 1.59 times higher than those from the previous numerical study that also involved the usage of a grooved Ce:Nd:YAG rod. A laser beam merging scheme is also presented, enabling the extraction of a single TEM₀₀-mode laser beam from the seven rods. A TEM₀₀-mode laser power of 207.55 W was attained, corresponding to collection and solar-to-laser power conversion efficiencies of 41.51 W / m² and 4.37%, respectively.