The surface of a commercial Y3Al5O12：Ce^3＋ phosphor was modified by 99% NH_4F＋CH_3COOH solution in a supersonic bath with water temperature of 80 oC for 4 h. The scanning electron microscopy（SEM） results showed t...The surface of a commercial Y3Al5O12：Ce^3＋ phosphor was modified by 99% NH_4F＋CH_3COOH solution in a supersonic bath with water temperature of 80 oC for 4 h. The scanning electron microscopy（SEM） results showed that the edge angles were not as sharp as the unmodified particles and the flat surfaces turned rough with many micro-structures covered. Positron lifetime measurements quantitatively showed that surface defects were removed away by more than 50%. As a result, the photoluminescence determinations showed that the backscatter loss was reduced by 4.2% and the emission power was enhanced by 5.6% after the surface modification. The conversion efficiency was greatly improved from 47.3% to 51.1%, as presented by the fluorescence images. Therefore, it would be greatly helpful for the improvement of efficiency, transparency and stability of pc-LED. Moreover, this method was significantly suitable for mass production due to its easy operation and low cost.展开更多
基金Project supported by National Natural Science Foundation of China(11175049,51177017)
文摘The surface of a commercial Y3Al5O12：Ce^3＋ phosphor was modified by 99% NH_4F＋CH_3COOH solution in a supersonic bath with water temperature of 80 oC for 4 h. The scanning electron microscopy（SEM） results showed that the edge angles were not as sharp as the unmodified particles and the flat surfaces turned rough with many micro-structures covered. Positron lifetime measurements quantitatively showed that surface defects were removed away by more than 50%. As a result, the photoluminescence determinations showed that the backscatter loss was reduced by 4.2% and the emission power was enhanced by 5.6% after the surface modification. The conversion efficiency was greatly improved from 47.3% to 51.1%, as presented by the fluorescence images. Therefore, it would be greatly helpful for the improvement of efficiency, transparency and stability of pc-LED. Moreover, this method was significantly suitable for mass production due to its easy operation and low cost.
