Spectral Properties of Yellow Fluorescent Powder for White LEDs
摘要
Much attention has been paid to white LEDs because of their potential applications in the illumination.The doping of rare earth ions plays an important role in the optical properties of yellow fluorescent powder.And mainly aiming to raise the intensity and the luminous rate of the white LEDs and by photoluminescence and electroluminescence,the luminescence spectrum of yellow fluorescent powder bought from different places is measured.Furthermore, the luminous intensity in the normal direction and the angle distribution of half maximum power for the white LEDs packed with cylindrical Φ5 epoxy on the same blue GaN chips are also measured under the same manufacture conditions. The results show that the yellow fluorescent powder bought from China mainland has higher optical output rate than that bought from China Taiwan and hence is more suitable to fabricate the white LEDs for practical use.