[GaN-based white-light-emitting diodes with low color temperature and high color rendering index].

The luminescence properties of high color rendering white LED depending on the proportions of mixed phosphor powders were investigated by adopting green and red phosphors stimulated by a 440 nm InGaN/GaN based blue LED. The results show that when the proportion of A/B type silica gels and green/red phosphor powders is 0.5 : 0.5 : 0.2 : 0.03, two luminance bands are stimulated and their wavelength peaks are 535 and 643 nm, respectively. The minimum color temperature can reach 3 251 K, while the color rendering is as high as 88. 8. Compared with the traditional white LED fabricated by yellow YAG-phosphors-coated high efficiency 460 nm blue LED, the color temperature is lower and the color rendering index can be increased by almost 26%.

High-efficiency InGaN-based LEDs grown on patterned sapphire substrates.

GaN films grown on PSS are investigated by XRD, CL, SEM and TEM. There are low threading dislocations (TDs) with larger fill factor, which results in better electrostatic discharge (ESD) yield of LEDs. The effect of growth rate on dislocations in GaN films grown on PSS is investigated by TEM. It is found that dislocations density decreases as the growth rates decrease. And the performance of InGaN-based LEDs on different PSS is analyzed. The performance of LEDs grown on different PSS is determined by slanted angle and fill factor simultaneously.