resumo
This work reports a simple hydrothermal route using citric acid as a "shape modifier" for the controlled synthesis of luminescent TbPO(4):Eu nanocrystals. The size and morphology of products change remarkably when the proportion of citric acid involved in the reaction increases. The multiple roles that citric acid plays during the controlled synthesis are discussed to try to understand the crystallization and growth dynamics of TbPO(4) crystals. The photoluminescence properties of TbPO(4):Eu are investigated. The excitation spectra and the variation of the (5)D(4) lifetime values as a function of the Eu(3+) concentration points out the occurrence of Tb(3+)-to-EU(3+) energy transfer, resulting in a maximum absolute emission quantum yield of 0.14. The possibility to tune the size, the shape, and the optical properties of the nanocrystals reported in this work might be useful for applications in optoelectronics or biolabeling. Moreover, this simple approach might also be applied for the synthesis of other luminescent phosphates.
palavras-chave
SHAPE-CONTROLLED SYNTHESIS; LIQUID-PHASE SYNTHESIS; IONIC LIQUIDS; LAPO4-CE,TB NANOCRYSTALS; SILVER NANOPARTICLES; QUANTUM DOTS; NANOSTRUCTURES; PARTICLES; NANORODS; SURFACE
categoria
Chemistry; Science & Technology - Other Topics; Materials Science
autores
Di, WH; Willinger, MG; Ferreira, RAS; Ren, XG; Lu, SZ; Pinna, N
nossos autores
Maria Rute de Amorim e Sá Ferreira André
Professor Catedrático
Nicola Pinna
Investigadoragradecimentos
This work was partially supported by the National Natural Science Foundation of China (Grant No. 5050203 1), Natural Science Foundation of Jilin Province (Grant No. 20060522), FCT Project No. (PTDC/CTM/65667/2006) and Grant No. (SFRH/BPD/40881/2007), and FAME network of excellence. W.D. is grateful for the special starting research fund for the Awardees of President Prize of Chinese Academy of Sciences (2008-2009).