Simultaneous tuning for excitation and emission of N doped Sr2SiO4:Eu for white light LEDs

Tunable color point and efficient excitation are two important challenges for improving white light LEDs. In this paper, red-shift in the emission spectra of Sr2SiO4:Eu has been achieved, and the excitation band has been tuned to fit the blue LED chips simultaneously by doping N into the host. XRD results showed that the unit cell volume markedly increased after nitridation. Moreover, nitridation resulted in the increase in weight loss, which can be attributed to the substitute of Si–O bonds by Si–N bonds. The effect of nitridation on the luminescence properties was well discussed.