tailieunhanh - Báo cáo hóa học: " Efficient manganese luminescence induced by Ce3+-Mn2+ energy transfer in rare earth fluoride and phosphate nanocrystals"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Efficient manganese luminescence induced by Ce3+-Mn2+ energy transfer in rare earth fluoride and phosphate nanocrystals | Ding et al. Nanoscale Research Letters 2011 6 119 http content 6 1 119 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Efficient manganese luminescence induced by I H I z Ce -Mn energy transfer in rare earth fluoride and phosphate nanocrystals Yun Ding Liang-Bo Liang Min Li Ding-Fei He Liang Xu Pan Wang Xue-Feng Yu Abstract Manganese materials with attractive optical properties have been proposed for applications in such areas as photonics light-emitting diodes and bioimaging. In this paper we have demonstrated multicolor Mn2 luminescence in the visible region by controlling Ce3 -Mn2 energy transfer in rare earth nanocrystals NCs . CeF3 and CePO4 NCs doped with Mn2 have been prepared and can be well dispersed in aqueous solutions. Under ultraviolet light excitation both the CeF3 Mn and CePO4 Mn NCs exhibit Mn2 luminescence yet their output colors are green and orange respectively. By optimizing Mn2 doping concentrations Mn2 luminescence quantum efficiency and Ce3 -Mn2 energy transfer efficiency can respectively reach 14 and 60 in the CeF3 Mn NCs. Introduction The preparation of fluorescent nanomaterials continues to be actively pursued in the past decades. The potentially broad applicability and high technological promise of the fluorescent nanomaterials arise from their intrinsically intriguing optical properties which are expected to pale their bulk counterparts 1-4 . Particularly controllable energy transfer in the nanomaterials has been receiving great interest because it leads luminescence signals to outstanding selectivity and high sensitivity which are important factors for optoelectronics and optical sensors 5 . Great efforts have been devoted to Mn2 -doped semiconductor nanocrystals NCs due to their efficient sensitized luminescence 6 7 . When incorporating Mn2 ions in a quantum-confined semiconductor particle the Mn2 ions can act as recombination centers for the excited electron-hole pairs and result .