LED用黄绿色荧光粉LiZnPO_4:Mn^(2+),Al^(3+)的合成及Al^(3+)敏化发光研究

Synthesis and Al^(3+) sensitized luminescence of green-yellow emitting phosphor LiZnPO_4:Mn^(2+),Al^(3+) for LED

为了获得可用于发光二极管(LED)的新型黄绿色荧光粉,用高温固相法合成了Li_(1-x)Zn_(0.9-x)PO_4:Mn_(0.1),Al_x系列的荧光粉。用XRD表征并分析了样品,获悉样品具有LiZnP04的结构。用荧光发射光谱及激发光谱表征了样品的发光性能,讨论了Al^(3+)掺杂对LiZnPO_4:Mn,Al荧光粉发光性能的影响。结果表明:Al^(3+)掺杂量对激发及发射光强度的影响均为开口向下、有极值的抛物线,Al^(3+)的最佳掺杂量为3%,对应样品是Li_(0.97)Zn_(0.87)PO_4:Mn_(0.1),Al_(0.03);Al^(3+)最佳掺杂量样品的发光强度是未掺Al^(3+)样品的3.98倍,说明在LiZnPO_4基质中Al^(3+)对Mn^(2+)的发光具有增敏作用;Al^(3+)的掺入只影响Mn^(2+)的发光强度,不影响Mn^(2+)的发光模式。Li_(0.97)Zn_(0.87)PO_4:Mn_(0.1),Al_(0.03);的色坐标值表明,该样品为黄绿色荧光粉,其在紫外线激发LED领域具有潜在的应用前景。

A series of Lil-xZn0.9-xPO4： Mn0.1, AL phosphors are prepared by the solid-state method to obtain a new green-yellow phosphor that can be applied for the light emitting diodes （LED）. XRD results confirm that the samples contain LiZnPO4 phase of crystals. Photoluminescence properties of the samples are characterized with photoluminescence of excitation （PLE） and emission spectra （PL）, and the effect of Al3＋ doping on the PL and PLE properties of Lil-xZno.9-xPO4： Mn0.1, AL phosphors is discussed. The results indicate that the dependent curve of relative intensity for PLE and PL on Al3＋ doping concentration is a parabola curve with mouth downward and maximum value, and the optimal molar concentration of Al3＋ for the samples is 3%, with corresponding sample being Lio.97ZnosTPO4： Mn0.1, Al0.03. The research results indicate that the peak area of emission bands of Li1-xZno.9-xPO4： Mn0.1, Alx with the optimal x is 3.98 times of that of sample with x=0. The fact suggests that the Al3＋ ions can enhance the emission of Mn2＋. Furthermore, Al3＋ doping only affects the intensity of Mn2＋ emission, and cannot influence its mode. The value for chromaticity coordinate of Lio.97Zno.s7 PO4： Mn0.1, A10.03 indicates that it is a green-yellow emitting phosphor, which can be potentially useful as a UV excited phosphor for LEDs.