| 초록 |
The interesting excitation and emission spectra, high chemical stability, small thermal quenching, and high quantum efficiency of nitride phosphors have activated intense study and practical applications. Some applications related to luminescent properties of nitride phosphors include white-light-emitting diodes (LEDs). In nitride compounds, the luminescent centers (usually rare earth ions) are bonded to nitrogen, which yields a different crystal-field environment from oxide com-pounds. The nitrogen-rich surrounding would generate a strong nephelauxetic effect and/or a large crystal-field splitting, leading to the unique luminescence of nitride compounds such as red shifted excitation and emission, high quantum efficiency and small thermal quenching. For example, a-sialon:Eu2+, b-sialon:Eu2+, SrSi2O2N2:Eu2+, Sr2Si5N8:Eu2+, and CaAlSiN3:Eu2+ nitride phosphors can be efficiently excited by blue light, and emit intense yellow, green, and red colors, respectively. Although a large family of nitride compounds has been reported, in comparison with the conventional oxide phos-phors, nitride phosphors, especially ternary or multinary nitride phosphors, have not been studied extensively. |
