Preparation, characterization, and application of a red phosphor Ca2InTaO6:Eu3+ in w-LEDs and latent fingerprint detection

Eu3+-doped Ca2InTaO6 phosphors were synthesized by a high-temperature solid-state reaction. Their crystal structure, composition, phase purity, photoluminescence (PL) properties, and thermal quenching mechanism were investigated in this experiment. The band gap of Ca2InTaO6 (3.87 eV) classifies it as an indirect band gap material. X-ray diffraction results confirm the good phase purity of the synthesized material has good phase purity. The Ca2InTaO6 lattice has an orthorhombic structure, which includes the Pnma(No. 62) space group. After being excited at 395 nm, Ca2InTaO6:0.40Eu3+ phosphor showed a red emission peak at 613 nm (5D0→7F2 transition). The optimal doping concentration of Ca2InTaO6:xEu3+ phosphor is x = 0.40. Moreover, Ca2InTaO6:0.40Eu3+ phosphor has a color purity of 99.9%, an internal quantum efficiency (IQE) of up to 90.69% and a thermal activation energy (Ea) of 0.36 eV. The prepared white light-emitting diode (w-LED) possesses satisfactory color rendering index (Ra = 88.3), correlation color temperature (CCT = 5748 K), and Commission International de L′Eclairage (CIE) coordinates (0.327, 0.339). The levelsⅠ-Ⅲ characteristics of the latent fingerprint (LFP) created by Ca2InTaO6:Eu3+ phosphor can also be clearly reflected. These experimental results show that Ca2InTaO6:Eu3+ phosphor can be applied in w-LED production and LFP detection.