Self-reduction synthesis and luminescence properties of Eu, Dy co-doped SrMg2 (PO4 )2 phosphor.

A series of SrMg2 (PO4 )2 :Eu2+ -Eu3+ ,Dy3+ phosphors was synthesized successfully using a high-temperature solid-state method in an air atmosphere. The structures were studied in detail using X-ray diffraction (XRD) and the luminescence properties of the samples. SrMg2 (PO4 )2 :Eu2+ -Eu3+ samples can emit adjustable blue-violet light by controlling the proportion of dopant concentration of europium and dysprosium under 340 nm excitation. Dy3+ exhibits typical blue and yellow emission under 350 nm excitation. The energy transferred from Eu3+ to Dy3+ in Dy and Eu co-doped system was determined by comparing the fluorescence spectra of single-doped system. In addition, the colour coordinates of the International Commission on lighting (CIE) indicated that SrMg2 (PO4 )2 :Eu2+ -Eu3+ ,Dy3+ could be considered as a potential blue-purple phosphor for white light-emitting diode applications.

In-air self-reduction synthesis and colour tunable luminescence from SrBPO5 :Eu2+ -Eu3+ excited using ultraviolet light.

SrBPO5 :Eu2+ -Eu3+ phosphors were synthesized using a conventional solid self-reduction reaction in an air atmosphere. Samples were characterized using thermogravimetry analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectra, fluorescence spectra and Commission International de l'Eclairage (CIE) data. The results of TGA and DSC showed that the raw materials could completely react at 1000°C. FTIR spectra and XRD results displayed that europium ions of different concentrations do not effect the structure of the hosts. Fluorescence spectra displayed that europium ions exist in bivalent and trivalent forms, and that the emission peak at 403 nm was attributed to the typical 5d-4f transition for Eu2+ ; 597 nm and 620 nm emissions were assigned to the characteristic transitions of 5 D0 -7F1, 2 for Eu3+ . CIE results depicted that the colour tone of the phosphors could be macro-controlled from blue to purple by controlling the doping amount of Eu3+ .Therefore, relative luminescence intensity between Eu2+ and Eu3+ could be adjusted by controlling the doping concentration of europium to tune the luminescence colour of SrBPO5 .

Preparation of LaF3:Eu3+ Based Inorganic-Organic Hybrid Nanostructures via an Ion Exchange Method and Their Strong Luminescence.

Lanthanide doped inorganic-organic hybrid nanostructures have received much attention in recent years due to their strong luminescence sensitized by organic ligands via an energy transfer route. In this work, an ion exchange method was used to prepare Eu3+ doped LaF3 based inorganic-organic hybrid nanostructures with organic ligands. The undoped LaF3 nanoparticles were first synthesized by a hydrothermal method, and Eu3+ ions were then ion exchanged into these LaF. nanoparticles to form the Eu3+ doped LaF3 nanoparticles, which were then used to prepare the inorganic-organic hybrid nanostructures with benzoic acid and 2-thenoyltrifluoroacetone. As a result of the luminescence sensitization, strong luminescence was observed in these inorganic-organic hybrid nanostructures, and the luminescence enhancement was over 40 times. Dependence of the luminescence of the hybrid nanostructures on the doping concentration and amount of organic ligands was studied in detail, and optimization was conducted to obtain the maximum luminescence for the hybrid nanostructures.