Novel red-emitting Sr3LaTa3O12:Eu3+ phosphor with high color purity and stability for w-LEDs and visualization of latent fingerprint

Novel red-emitting phosphors, Sr3LaTa3O12:Eu3+ (SLTO:Eu3+), have been successfully synthesized for use in white light-emitting diodes (w-LEDs) and latent fingerprint (LFP) visualization applications. The crystalline structure, bandgap, and photoluminescence (PL) of the SLTO:Eu3+ phosphors were thoroughly investigated. Under 395 nm excitation, SLTO:Eu3+ phosphors emitted orange-red light at the wavelength of 616 nm due to the 5D0-7F2 transition of Eu3+ ions. The optimal doping concentration of the phosphor is x = 0.30 and the neighbor ions interaction is the most critical factor in the concentration quenching mechanism of the SLTO:Eu3+ phosphor. Furthermore, the SLTO:0.30Eu3+ phosphor exhibit higher thermal stability compared to the conventional red phosphor (Sr2Si5N8:Eu2+). The packaged w-LED showed a correlated color temperature (6887 K), excellent color rendering index (95), and Commission International de l'Eclairage (CIE) coordinates of (0.305, 0.334). The SLTO:0.30Eu3+ phosphor effectively detected level 1–3 structures of LFPs under ultraviolet irradiation, and ultimately detected LFPs in various daily life circumstances. These findings indicate that the SLTO:0.30Eu3+ phosphor might be a viable option for w-LED lighting applications and LFPs visualization.