Deep red SrLaGa3O7:Mn4+ for near ultraviolet excitation of white light LEDs

摘要

Red luminescent phosphor SrLaGa3O7:Mn4+ was prepared by the traditional high-temperature solid-state reaction. The structural characteristics, luminescence properties and the performance of this phosphor were investigated in light-emitting diode devices. Deep red emission peaking at similar to 715 nm was observed under the excitation wavelength in the range of 220-550 nm, which is related to the charge transfer band of Mn4+-O2- and the (4)A(2g) -> T-4(1g), (4)A(2g) -> T-2(2g) and (4)A(2g) -> T-4(2g) transitions of Mn4+. In particular, SrLaGa3(1-x) O-7:3xMn(4+) exhibits the strongest absorption in the near ultraviolet region (350-410 nm). This feature can well match the emission of current commercial near-ultraviolet chips, and is expected to be used in white LEDs. Moreover, we also conducted a thermal quenching experiment on the SrLaGa3O7:Mn4+ phosphor, and the obtained activation energy was 0.4 eV, indicating that the quenching temperature is (T-50%) 370 K. Finally, the application of the SrLaGa3O7:Mn4+ phosphor in constructing a LED device was explored. At a driving current of 20 mA, the Commission on Illumination (CIE) coordinates of the device are (0.3281, 0.3080), with a high color rendering index (CRI) of 91.9 and a low corresponding color temperature (CCT) of 4315 K. Experimental results show that the phosphor has broad prospects in preparing white LED devices excited by near-ultraviolet light.

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