蓝光激发余辉型荧光粉的研究进展

白光LED具有节能、环保、响应速度快等优点,逐渐成为新一代照明光源,其普遍采用蓝光LED芯片激发黄色YAG∶Ce3+荧光粉合成白光的模式。由于这类LED加入直流(DC)/交流(AC)转换器和散热器,使得市售灯具价格偏高,严重阻碍了白光LED的进一步推广。AC-LED采用市电直接驱动,是LED发展的必然方向,余辉型荧光粉使得AC-LED变成了可能。主要针对应用于AC-LED的具有蓝光激发余辉功能的荧光粉的国内外研究现状进行了总结,并对用于消除LED频闪的余辉发生时间、余辉时间长度进行了计算,对余辉强度、余辉衰减速率进行了初步判断,得出荧光粉的余辉时间为6.67ms≤Tx≤10ms,余辉强度最小值需大于0.032mcd/m2,余辉衰减速率满足式(1),且余辉发生在T/2~2T/3时对于消除频闪最有益。

Advances in Persistence Phosphors Activated by Blue-light

As it is energy savings ,environmental friendliness and fast switching ,white light-emitting diode (w-LED) has be-come the new generation of lighting sources .It is commonly used that applying blue LED chip to excite the yellow YAG:Ce3+ phos-phor to synthesis white light .However ,adding the DC (direct current)/AC (alternating current) conversion and heat-dissipation ra-diators makes the w-LED too expensive ,which restricts the further development of w-LED seriously .AC-LED ,a LED device driven by city power ,is the inevitable direction of LED development .Furthermore ,it is possible that applying afterglow phosphors in AC-LED .This paper provides a review of the persistence phosphors motivated by blue light in AC-LED ,and the length of afterglow time is calculated .What's more ,the afterglow intensity and the decay rates are analyzed at the same time .The results of the paper showed that the afterglow decay time of phosphors is Tx (6.67 ms≤ Tx ≤10 ms) ,and the minimum value of afterglow intensity is greater than 0.032 mcd/m2 .Meanwhile ,the decay rate of afterglow satisfied the forum (1) in the text ,and the afterglow is occurred at T/2—2T/3 ,which is the most beneficial to eliminate flicker effect .