Design of a Novel Scandium Silicate Based Blue-Emitting Phosphor with High Efficiency and Robust Thermal Stability for Warm WLEDs and Field Emission Displays
A novel blue-emitting phosphor, Na3ScSi2O7: Ce3+ (NSSO: Ce3+), was synthesized with a solid-state method at low temperature successfully. Its crystal structure, band structure, photoluminescence and cathodoluminescence properties were researched in detail. The phase formation and the crystal structure were confirmed by powder X-ray diffraction analysis and Rietveld refinement method, respectively. Under the excitation of n-UV light, the optimal NSSO: 0.02Ce3+ phosphor can yield blue emission centered at 452 nm with high quantum efficiency of 50.9%. The PL intensity of NSSO: 0.02Ce3+ phosphor remains 71.46% of the initial value when the temperature rising from room temperature to 150 oC, indicating a good thermal stability. A WLED lamp was obtained by combing 360 nm n-UV chip with Sr2SiO4: Eu2+, (Ca, Sr)AlSiN3: Eu2+ and NSSO: 0.02Ce3+ phosphors, in which the color coordinates, CCT and CRI are (0.360, 0.348), 4409 K and 90.9, respectively. Moreover, under low voltage electron bombardment, the phosphor can emit blue emission with high luminescent intensity, current saturation and resistance. All the results indicate that the NSSO: Ce3+ phosphor show much potential for the application of both WLEDs and field emission displays (FEDs). Our research has also offered a new insight and perspective that using Sc-based sorosilicates as host can be a proper strategy for developing excellent inorganic luminescence materials.