Mechanoluminescence(ML) directly converts mechanical energy into light, offering a promising route for energy-free sensing. Here, we report a low cost, stable Al₂O₃:Cr³⁺ platform with self-recoverable near-infrared emission. A reversible stress induced ionization–recapture mechanism, together with defect engineering, annealing, and heterostructure optimization, delivers strong and recoverable luminescence. The material enables flexible ML paper and alloy-surface coatings for real time structural stress visualization.

Researchers demonstrate a giant insulator-to-metal transition and room-temperature superparamagnetism by controlling defect reconstruction and nickel nanoparticle formation in perovskite oxide thin films.

Quantum cascade laser (QCL) frequency combs face bandwidth limitations (~100 cm⁻¹) that challenge carrier-envelope offset frequency locking. This work demonstrates ultra-broadband QCLs using a diagonal multi-state-to-continuum active region design, achieving ~600 cm⁻¹ electroluminescence at 298 K. Devices deliver 2.72 W peak power with 1.2 μm lasing bandwidth and 1.93 μm at 80 K, advancing single-stack mid-infrared semiconductor lasers for spectroscopy and communications.