Design efficient energy transfer Ca2Al2SiO7: Bi3+, Eu3+ phosphors by cationic substitution for full-spectrum W-LED lighting

Abstract

High lighting quality has become essential in indoor lighting with the continuous technological innovations in the illumination field. The existing mainstream white light implementation cannot completely cover the entire visible light area, whether it is a combination of a blue chip and YAG: Ce3+ (red gap and deep-blue gap) or a combination of an ultraviolet chip and three-color phosphor (cyan gap and deep-blue gap. This study uses Bi3+ as the luminescence center to obtain an efficient deep-blue emission phosphor through local lattice control (Internal Quantum Efficiency = 65%). Subsequently, a Bi3+-Eu3+ energy transfer system with a transfer efficiency of 97.15% was designed to obtain a double emission of deep-blue and red in Ca2Al2SiO7: 0.06Bi3+, 0.04Eu3+ (Internal Quantum Efficiency = 81%). The energy transfer between Bi3+-Eu3+ increases the emission integration intensity to 149% compared to single-doped Eu3+, and the CASO: 0.06Bi3+, 0.04Eu3+ thermal quenching resistance is excellent (3.8% integral strength loss at 425 K). Finally, 395 nm and 310 nm phosphor conversion (pc) W-LED devices with color rendering indexes of 84.2 and 91.6 were prepared by combining CASO: 0.06Bi3+, 0.04Eu3+ and commercially available phosphors, respectively. This result shows that these phosphors can be applied in full-spectrum white illumination.