Structural and optical properties of Cd2MgTeO6:Dy3+, Na+ phosphors for potential application in w-LEDs and personal identification

Abstract

Cd2MgTeO6:Dy3+, Na+ phosphors were synthesized via a high-temperature solid-phase reaction. Phase purity, structure, surface morphology, luminescent properties, and thermostability of the samples were analyzed exactly. Under 351 nm excitation, Cd2MgTeO6:Dy3+, Na+ phosphors possessed three emission peaks: 4F9/2-6HJ/2 (J = 15, 13, 11). The phosphors mainly emitted yellow light due to the intensity of 4F9/2-6H13/2 being higher than other energy level transitions. The optimal doping concentration of Cd2MgTeO6:xDy3+, xNa+ phosphor was x = 10 mol% and the mechanism of concentration quenching was the quadrupole-quadrupole interaction. The phosphors possessed good thermostability and high activation energy (Ea = 0.41 eV). The chromaticity coordinate (CIE) coordinates of Cd2MgTeO6:Dy3+, Na+ were located yellow region and were almost the same at different doping concentration. For Cd2MgTeO6: 10 mol%Dy3+, 10 mol%Na+ phosphor, the internal quantum efficiency (IQE) was 20.55% and the cell viability for the cytotoxicity test was bigger than 88.1%. White-light emitting diode (w-LED) was fabricated with an excellent correlated color temperature (CCT = 5340 K) and a high color rendering index (CRI = 88). Cd2MgTeO6:10 mol%Dy3+, 10 mol%Na+ phosphor could display the feature of latent fingerprint (LFP) and lip print (LP) excellently. Hence, the phosphor could excellently apply to the three-level features of latent fingerprint and six characteristics of lip print identification. In general, Cd2MgTeO6:Dy3+, Na+ phosphors have great potential in w-LEDs and personal identification.