Highly-efficient near-infrared emission from Cr3+ activated LaMgAl11O19 phosphor toward optical thermometer and pc-LED applications

There is strong demand of exceptional efficiency for near-infrared (NIR) phosphors for next-generation integrated and intelligent multifunctional light-emitting diode (LED) devices. Designing NIR phosphors with excellent efficiency that simultaneously meet multiple application requirements is challenging. Hence, this work focuses on the NIR optical properties and the corresponding multifunctional applications for Cr 3+ activated LaMgAl 11 O 19 (LMAO) phosphors. The blue light excitable LMAO:Cr 3+ phosphors can produce intense NIR emission ranging from 630 to 1000 nm with an 95.8% internal quantum efficiency as well as excellent thermal stability (I 423 K /I 303 K = 75.9%). Additionally, benefiting from the strong correlation between fluorescence lifetime and ambient temperature, the LMAO:Cr 3+ phosphors were showed promising potential for application in temperature sensing. Notably, the NIR phosphor-converted LED devices based on LMAO:Cr 3+ phosphors and commercial blue LED chip were self-built, which exhibiting great potential for indoor plant cultivation, night vision, and nondestructive detection. This study describes the highly efficient LMAO:Cr 3+ phosphors preparation and the corresponding multifunctional applications in the fields of optical thermometry, indoor plant cultivation, night vision, and nondestructive detection, which is crucial for the next-generation integrated and intelligent multifunctional LED devices.