Hexagonal β-NaYF4 co-doped with Yb3＋ and Er3＋ is directly synthesized under mild conditions using a hydrothermal method.The variation of the ratio of Ln3＋ to F-and ethylenediaminetetraacetic acid（EDTA） causes th...Hexagonal β-NaYF4 co-doped with Yb3＋ and Er3＋ is directly synthesized under mild conditions using a hydrothermal method.The variation of the ratio of Ln3＋ to F-and ethylenediaminetetraacetic acid（EDTA） causes the shape of the microcrystal to change from microplate to microcolumn.The NaYF4 powder is mixed with polydimethylsiloxane（PDMS） to create an up-converter for thin film amorphous silicon solar cells so as to evaluate the effectiveness of the synthesized material as an up-converter.In order to overcome the difficulty in measuring the effectiveness of up-conversion material,a new method of using near infrared illumination to measure the short circuit current densities of solar cells both with and without up-converters is developed.An up-converter with pure hexagonal NaYF4：Yb3＋/Er3＋ microcrystal produces a high current output.Emission intensity data obtained by photoluminescence suggest that pure hexagonal NaYF4：Yb3＋/Er3＋ microcrystals are more efficient than nanocrystals when used as up-converting phosphors.展开更多
基金Project supported by the National Basic Research Program of China (Grant Nos. 2011CBA00705,2011CBA00706,and 2011CBA00707)the National Natural Science Foundation of China (Grant No. 60976051)+1 种基金the Science and Technology Support Program of Tianjin,China (Grant No. 12ZCZDGX03600)the Program for New Century Excellent Talents in University of China (Grant No. NCET-08-0295)
文摘Hexagonal β-NaYF4 co-doped with Yb3＋ and Er3＋ is directly synthesized under mild conditions using a hydrothermal method.The variation of the ratio of Ln3＋ to F-and ethylenediaminetetraacetic acid（EDTA） causes the shape of the microcrystal to change from microplate to microcolumn.The NaYF4 powder is mixed with polydimethylsiloxane（PDMS） to create an up-converter for thin film amorphous silicon solar cells so as to evaluate the effectiveness of the synthesized material as an up-converter.In order to overcome the difficulty in measuring the effectiveness of up-conversion material,a new method of using near infrared illumination to measure the short circuit current densities of solar cells both with and without up-converters is developed.An up-converter with pure hexagonal NaYF4：Yb3＋/Er3＋ microcrystal produces a high current output.Emission intensity data obtained by photoluminescence suggest that pure hexagonal NaYF4：Yb3＋/Er3＋ microcrystals are more efficient than nanocrystals when used as up-converting phosphors.
