Reversible laser-printing perovskite quantum dots in glass via lanthanide doping

• • 2 mol% Lu2O3 doping reduces the Si-O tensile vibration at 1039 cm-1 to its lowest frequency and intensity, producing the loosest glass network and shortest self-recovery time; this threshold defines the optimal window for reversible laser erasure, as over-doping (higher field strength) creates a rigid network that permanently prevents erasure. • • Erased PeQD patterns autonomously regenerate at 45% relative humidity, with recovery time varying by lanthanide type and concentration; this humidity-driven regeneration eliminates the need for thermal annealing, enabling ambient-condition reset for encryption devices. • • The write-erase-recovery cycle maintains stable luminescence over multiple iterations, supporting 4x6 code arrays and Quick Response codes that are invisible in daylight, UV-decodable, and selectively erasable by low-power fs laser; this provides a tamper-evident anti-counterfeiting platform with rewriteable data storage. • • Lanthanide doping controls the crystallization barrier by destroying bridging oxygen (Si-O) bonds; the resulting ionic diffusion space lowers the barrier for CsPbBr3 formation and decomposition, establishing a direct composition-structure-property relationship for glass-based PeQD devices.