Synthesis and optical properties of new red-emitting SrBi2Ta2O9:Eu3+ phosphor application for w-LEDs commercially based on InGaN.

In the present work, a novel Eu3+-doped SrBi 2 Ta 2 O 9 red-emitting phosphor has been successfully synthesized by solid-state reaction. The X-ray diffraction (XRD) and luminescence properties of SrBi 2 Ta 2 O 9 have been investigated in detail. Under the excitation of λ = 395 nm and λ = 465 nm, the phosphor can emit bright red light at 615 nm due to 5D 0 →7F 2 transition. The optimal doping concentration and the thermal stability are investigated. Compared with reported commercial Y 2 O 2 S:Eu3+, Y 2 O 3 :Eu3+, the Commission International de L'Eclairage (CIE) coordinates of the red phosphor SrBi 2 Ta 2 O 9 :0.10Eu3+ are much closer to the standard of the National Television System Committee (NTSC). The value of color purity is 97%. The luminescence lifetime of SrBi 2 Ta 2 O 9 :Eu3+ is measured. Moreover, the white light emitting diode (w-LED) can be manufactured on the basis of InGaN. The chromaticity coordinates of combined w-LED are (0.327, 0.350), which approximates the equal energy point (0.333, 0.333). [ABSTRACT FROM AUTHOR]