Real Competitors to Ruby: The Triel Oxonitridoborates AlB4O6N, Al0.97Cr0.03B4O6N, and Al0.83Cr0.17B4O6N (Adv. Funct. Mater. 28/2024)

Ruby 2.0 In article number 2400054, Markus Suta, Hubert Huppertz, and co‐workers present a new oxonitridoborate with an exceptionally efficient red line emission based on the octahedral coordination of the luminescent Cr3+ ion. Remarkably, AlB4O6N:Cr3+ fulfills the most important criteria of a possible alternative luminescent pressure sensor, enabling more precise pressure calibration in diamond anvil cells than the current gold standard ruby. The authors would like to thank Abraham Siedler and Marie‐Theres Wildauer for their commitment in designing the inside back cover.