KY(CO_(3))_(2):Sm^(3+)新型红光荧光粉的制备及其发光性能研究

Preparation and Luminescence Properties of KY(CO_(3))_(2):Sm^(3+)Novel Red Phosphor

为解决白光LED中因蓝光芯片激发黄色荧光粉而导致显色指数较低问题,采用水热法制备一种新型红光荧光粉KY(CO_(3))_(2):Sm^(3+)。通过X射线粉末衍射、光致发光光谱、色度坐标及荧光寿命等表征手段研究样品的物相结构及其发光性能。结果表明:掺入Sm^(3+)后,KY(CO_(3))_(2)的晶体结构并没有发生改变。随着Sm^(3+)掺杂量的增加,荧光粉的发光强度先增强后减弱,最佳掺杂浓度为10%。Dexter理论分析表明,Sm^(3+)的浓度猝灭归因于电偶极-电偶极相互作用机制。以596 nm作为监测波长,KY(CO_(3))_(2):Sm^(3+)荧光粉激发峰主要包含402 nm (6H_(5/2)→4F_(7/2))和474 nm (6H_(5/2)→4I_(13/2)) 2波长,表明该荧光粉可以被商用紫外LED芯片和蓝光LED芯片有效激发。改变Sm^(3+)掺杂比例,荧光粉色度坐标值基本保持不变,均位于标准红光区,因此KY(CO_(3))_(2):Sm^(3+)红光荧光粉有望作为白光LED用红光荧光粉。

In order to solve the problem of low color rendering index in white LEDs caused by blue-light chips exciting yellow-light phosphors,a novel red-light phosphor 3+KY(CO_(3))_(2):Sm was prepared by hydrother-mal method.The crystal structure and luminescent properties of the sample were characterized by X-ray pow-der diffraction,photoluminescence spectroscopy,color coordinates,and fluorescence lifetime measurements.The results showed that the crystal structure of KY(CO_(3))_(2) remained unchanged in the presence of Sm3+dop-ing.With the increase of Sm^(3+)doping,the luminescence intensity of phosphors initially increased and then de-creased.The optimal doping amount was found to be 10%.The concentration quenching mechanism was at-tributed to the electric dipole-electric dipole interaction by the analysis of Dexter relationship.The dominant fluorescence excitation peaks at 402 nm(6H_(5/2)→4F_(7/2))and 474 nm(6H_(5/2)→4I_(13/2))in the monitoring wavelength of 596 nm indicated that the phosphor could be effectively excited by commercial ultraviolet LED and blue LED.The color coordinates of the doped phosphors showed minimal changes in the red region,indicating that 3+KY(CO3)2:Sm could be utilized as red-light phosphors for white LEDs.