【摘要】 为了研究大功率LED的光衰机制,选用了一系列的大功率白光、蓝光发光二极管分别进行恒流点亮,在点亮不同时间阶段测量其光通量、发光谱及伏安特性。发现在光衰过程中,光通量有时会上升;通过LED光谱测定,发现光谱分布有明显变化;同时,pn结内阻也逐渐变大。研究表明大功率LED光衰有较为复杂的过程:其中荧光粉老化及pn结性能退化是最主要的。文章对此进行了初步的分析,为白光LED的应用及进一步研究白光LED衰减提供了参考。更多还原

【Abstract】 To study the mechanism about the luminous attenuation of high-power LEDs,a series of white and blue LEDs were lighted continuously under constant current,and the luminous flux,emission spectra and V/I characteristics were measured at different periods.In the process of luminous attenuation,luminous flux ascended abnormally sometimes.During the luminous attenuation,the emission spectrum varies significantly,and the resistance of pn junction is increased.This indicates that luminous attenuation of high-power LED is complex.Ageing of phosphors and deterioration of the LED luminescence are primary causes.The results will provide a reference to the application of white LED and for the further study.更多还原