【摘要】 本文报告蓝色InGaN基芯片和光转换黄绿色和红色荧光体结合的属于 345 0K、 2 90 0K及 2 70 0K低色温、高显色性白光LED的发射光谱、色品坐标、显色指数Ra、光效 η等性质以及这些光学特性与正向电流IF 的关系。揭示这些关系的变化及相关色温差ΔTc 的变化规律 ,并对这些结果进行讨论。在IF =2 0mA下 ,345 0K、 2 90 0K及2 70 0K低色温白光LED的光效 η (lm w)分别为 5 6. 4、 5 1 1.及 4 3 .3,它们的Ra均为 85左右。更多还原

【Abstract】 White LEDs which show low related color temperature in this area of 3450～2700K and high rendering index(Ra85) have been developed by combining green-yellow YAG∶Ce phosphor and red Cas:Eu 2+ phosphor with a InGaN-based blue chip(λ em 450～465nm). This paper reports on the emission spectrum, chromaticity coordinate, rendering index, luminous flux and luminous efficiency for variant white LEDs with low related color temperature. The characteristic changes at various forward-bias currents have been obtained and discussed. At I F20mA, the luminous efficiencies (η) of white LEDs with 3450K, 2900K and 2700K are 56.4, 51.1 and 43.3lm/w, respectively; and rendering index Ra are all about 85.;更多还原