A novel highly thermal-stable Ba2GdSbO6:Sm3+ phosphor with intrinsic deep-red emission for personal identification and plant cultivation LEDs

The novel Sm3+-activated Ba2GdSbO6 (BGSO) antimonate phosphors with double perovskite structure were first synthesized via a high-temperature solid-state reaction. The products' crystallographic structure, phase purity, micro-morphology, and luminescent properties were analyzed. The Ba2GdSbO6:Sm3+ phosphor could be effectively excited by 406 nm irradiation, and four sharp peaks accompanied by a broad band were presented. The dominant peak was located at 602 nm, corresponding to the typical 4G5/2 → 6H7/2 transition of Sm3+ ions, while the deep-red emission band at 675 nm is owing to the BGSO host intrinsic emission. Impressively, the product shows high thermal stability with its emission intensity of 88.8% at 420 K. Moreover, its thermal quenching temperature exceeds 480 K. The electroluminescent spectrum of the red light-emitting diode (LED) device fabricated by BGSO:0.02Sm3+ overlapped well with the absorption spectra of the phytochromes, suggesting its potential for plant cultivation light source. The sample with the best doping concentration was selected for surface modification with oleic acid (OA). In latent fingerprint and lip print detection, the phosphor showed high resolution, high contrast, and low background interference applied on different substrates. Hence, the BGSO:Sm3+ phosphor can be considered a promising material in plant cultivation LEDs and latent fingerprint and lip print visualization.