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

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。

Synthesis and Al3+ sensitized luminescence of green-yellow emitting phosphor LiZnPO4:Mn2+, Al3+ for LED

A series of Li_1-xZn_0.9-xPO₄:Mn_0.1, Al_x 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 Li_1-xZn_0.9-xPO₄:Mn_0.1, Al_x 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 Li_0.97Zn_0.87PO₄:Mn_0.1, Al_0.03. The research results indicate that the peak area of emission bands of Li_1-xZn_0.9-xPO₄:Mn_0.1, Al_x 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 Li_0.97Zn_0.87 PO₄:Mn_0.1, Al_0.03 indicates that it is a green-yellow emitting phosphor, which can be potentially useful as a UV excited phosphor for LEDs.