Abstract: In this paper,the effect of SiO2 coating on the luminescence and thermal properties of BaSi2O2N2∶ Eu2 + blue-green phosphors was investigated.The BaSi2O2N2 ∶ Eu2 + blue-green phosphor was coated with SiO2 by sol-gel method.The experimental results show that the optimal coating amount is 6wt;,the phosphor brightness is rapidly decrease when the amount larger than this value.After coating SiO2,the thermal quenching performance of BaSi2O2N2∶ Eu2+ phosphor at 150 ℃ was increased by 2.4;,and the luminescence performance of the phosphor after thermal degradation at 500 ℃ was increased by 15;.SiO2 coating significantly improves the thermal stability of BaSi2O2N2∶Eu2+ phosphors.The mechanism of SiO2 coating is that a blocking layer is formed between the surface of the phosphor and the oxidizing atmosphere protects the luminescent center of Eu2+ from being oxidizing during thermal heating.

Key words: In this paper,the effect of SiO2 coating on the luminescence and thermal properties of BaSi2O2N2∶ Eu2 + blue-green phosphors was investigated.The BaSi2O2N2 ∶ Eu2 + blue-green phosphor was coated with SiO2 by sol-gel method.The experimental results show that the optimal coating amount is 6wt;,the phosphor brightness is rapidly decrease when the amount larger than this value.After coating SiO2,the thermal quenching performance of BaSi2O2N2∶ Eu2+ phosphor at 150 ℃ was increased by 2.4;,and the luminescence performance of the phosphor after thermal degradation at 500 ℃ was increased by 15;.SiO2 coating significantly improves the thermal stability of BaSi2O2N2∶Eu2+ phosphors.The mechanism of SiO2 coating is that a blocking layer is formed between the surface of the phosphor and the oxidizing atmosphere protects the luminescent center of Eu2+ from being oxidizing during thermal heating.