Today we are discussing what are the advantages of converting purple LED lamp beads to white LED lamp beads?

  White LED lamp beads obtain blue light by exciting phosphors with purple LED lamp beads, and the peak intensity of blue light is not too high. Moreover, it can output all light in the wavelength range of visible light, so the light rendering index is relatively high, and ideal white light like sunlight can be realized. And its red light rendering index "R9" is particularly high, and the average rendering index "Ra" is also as high as 95.

  Ordinary blue LED chips are fabricated on sapphire substrates. Since GaN-based semiconductors differ from sapphire in lattice constants, etc., crystal defects called "dislocations" are prone to occur. However, with GaN substrates, there is almost no difference in lattice constants, so crystal defects are difficult to occur. Compared with products using sapphire substrates, the dislocation density can be reduced to about 1/1000.

  The violet LED chip is not prone to the problem of "droop". The decrease in luminous efficiency is a phenomenon in which the luminous efficiency decreases when the driving current density is increased in order to increase the luminous intensity, and it is also a major problem when increasing the brightness. On the other hand, the crystal quality of GaN on GaN type products is higher, and compared with sapphire substrate type products, the problem of light efficiency degradation is less likely to occur. Therefore, compared with the sapphire substrate type, the GaN substrate type product can increase the current density by 5 to 10 times.

  The purple LED chip is triangular, and the shape of the ordinary LED chip is quadrangle. Compared with the triangular LED chip, the light emitted by the light-emitting layer of the LED chip has a higher efficiency (light extraction efficiency) to the outside of the chip. Due to the high crystal quality and light extraction efficiency of violet LED lamp beads, the "WPE (wall-plug efficiency, electro-optical conversion efficiency)" obtained by dividing the light output by the input power can reach 84%. The WPE of ordinary blue light-emitting diodes is only 50 to 60%.

  Because the violet LED lamp bead is made of GaN substrate, the violet LED lamp chip is made by stacking GaN semiconductors on the GaN substrate, which belongs to the "GaN on GaN" type LED lamp bead. The crystal quality of the GaN semiconductor layer is relatively high, so the purple light LED lamp beads have high luminous efficiency, and the efficiency is improved quickly.

  The above is about the two advantages of violet LED lamp beads to obtain white LED lamp beads: improving luminous efficiency and high light rendering index