Yingda Qian

1 Introduction Nitride semiconductor-based devices are extensively utilized as highly efficient semiconductor materials due to their minimal environmental impact and tolerance to operate under extreme conditions, such as high temperatures and high pressures comparing to other semiconductors.

1. Introduction Solid-state lighting white LEDs based on nitride materials have attracted much attention because of their high efficiency, small volume, long lifetime, and environmental friendliness [1] [2] . Generally, the nitride materials doped with rare earth (RE) ions were considered as promising materials for LED chips and phosphors owing to their high stability and flexible bandgap adjustment in the visible light range. For the RE doped GaN, it has strong luminescence and high efficiency.