Controlled nucleation and crystal growth through nano SiO2 for enhancing the orange luminescence of (Sr,Ba)3SiO5: Eu2+ in white LEDs application.

Abstract: To enhance the luminescence of (Sr,Ba)3SiO5:Eu2+ for white light-emitting diodes, a new method for the synthesis of phosphor was developed. In the proposed method, the mixture of large and nano SiO2 particles as a silica source was employed to control the nucleation and crystal growth of the material. The impurity phase (Sr,Ba)2SiO4, which easily coexisted with (Sr,Ba)3SiO5 was suppressed. Accordingly, the luminescence was enhanced significantly by the partial substitution of conventional SiO2 with nano SiO2. The improvement in crystallinity and morphology was examined with XRD and SEM. Moreover, the sintering temperature and the concentration of nano SiO2 was optimized. The results show that appropriate amount of nano SiO2 has pronounced effects on the nucleus formation and crystal growth, while excessive crystal seeds formed may hinder the growth of particles. A mechanism for this improvement was proposed. [Copyright &y& Elsevier]