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
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Báo cáo hóa học: " Efficient manganese luminescence induced by Ce3+-Mn2+ energy transfer in rare earth fluoride and phosphate nanocrystals"Ding et al. Nanoscale Research Letters 2011, 6:119http://www.nanoscalereslett.com/content/6/1/119 NANO EXPRESS Open AccessEfficient manganese luminescence induced byCe3+-Mn2+ energy transfer in rare earth fluorideand phosphate nanocrystalsYun 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 centers in electroluminescent devices [10,11]. They mayThe preparation of fluorescent nanomaterials continues even find applications in future spin-based informationto be actively pursued in the past decades. The poten- processing devices [12,13] and have been examined astially broad applicability and high technological promise models for magnetic polarons [14]. Moreover, as emis- sion centers, Mn2+ ions can be used for the synthesis ofof the fluorescent nanomaterials arise from their intrin-sically intriguing optical properties, which are expected long persistent phosphors [15,16], and white-light ultra-to pale their bulk counterparts [1-4]. Particularly, con- violet light-emitting diodes [17], when doped in inorganictrollable energy transfer in the nanomaterials has been host materials (such as silicate, aluminate, and fluoride). Rare earth ions (such as Ce3+ and Eu2+) have been com-receiving great interest because it leads luminescence monly used as sensitizers to improve Mn2+ fluorescencesignals to outstanding selectivity and high sensitivity,which are important factors for optoelectronics and efficiency in bulk materials [18-20]. Typically, the efficientoptical sensors [5]. room temperature [RT] luminescence were reported in the Great efforts have been devoted to Mn2+-doped semi- Mn 2+ , Ce 3+ co-doped CaF 2 single crystal and otherconductor nanocrystals [NCs] due to their efficient sensi- matrixes, which were assigned to the energy transfer fromtized luminescence [6,7]. When incorporating Mn2+ ions the Ce3+ sensitizers to the Mn2+ acceptors through an elec-in a quantum-confined semiconductor particle, the Mn2+ tric quadrupole short-range interaction in the formed Ce3+- Mn2+ clusters [18]. However, a portion of isolated Ce3+ andions can act as recombination centers for the excitedelectron-hole pairs and result in characteristic Mn 2+ Mn 2+ ions which are randomly dispersed in the host( 4 T 1 - 6 A 1 )-based fluorescence. Compared with the usually causes a low Ce3+-Mn2+ energy transfer efficiency.undoped materials, the Mn2+-doped semiconductor NCs In this work, we have synthesized the CeF 3:Mn andoften have higher fluorescence efficiency, better photo- CePO 4 :Mn NCs and investigated the Ce-Mn energychemical stability, and prolonged fluorescence lifetime. transfer in these representative rare earth NCs. UponTherefore, such Mn 2+ -doped NCs have recently been UV light excitation, both the CeF3:Mn and CePO4:Mn show bright Mn2+ lu ...