Highly Flexible Oxide Ceramic Luminescent Membranes against Extreme Temperatures

Abstract Although high‐temperature operation (i.e., over 300 °C) is of tremendous importance for flexible photoluminescence applications, achieving mechanical and optical robustness for flexible photoluminescence devices at extreme temperatures is fundamentally challenging. Herein, a general strategy is provided to fabricate flexible photoluminescence membranes against extreme temperatures, made of rare earth fluorophore‐doped amorphous oxide ceramic nanofibers. When properly structurally designed, such flexible membranes display a temperature‐insensitive photoluminescence behavior with bright red luminescence over a wide temperature range from −12 °C up to a record 375 °C (648 K), and a remarkable luminescence and mechanical robustness without red emission color degradation when heated at 375 °C for a long time of 24 h (1440 mins), far beyond reported flexible luminescence materials. Importantly, for the first time, the microstructure of the amorphous oxide ceramic nanofiber is revealed, providing insights into the phosphor medium‐range ordered atomic packing ordering toughening the optical performance, presenting a potent strategy for designing highly temperature and deformation‐tolerant flexible luminescence materials and emphasizes the influence of atomic‐level structure on the properties of amorphous oxide nanofiber. This work opens a window for the design of flexible luminescence devices in extreme environments and will greatly promote the development of flexible optics.