Transition of Emission Colours as a Consequence of Heat-Treatment of Carbon Coated Ce3+-Doped YAG Phosphors

To modify the luminescence properties of Ce³⁺-doped Y₃Al₅O₁₂ (YAG) phosphors, they have been coated with a carbon layer by chemical vapor deposition and subsequently heat-treated at high temperature under N₂ atmosphere. Luminescence of the carbon coated YAG:Ce³⁺ phosphors has been investigated as a function of heat-treatment at 1500 and 1650 °C. The 540 nm emission intensity of C@YAG:Ce³⁺ is the highest when heated at 1650 °C, while a blue emission at 400–420 nm is observed when heated at 1500 °C but not at 1650 °C. It is verified by X-ray diffraction (XRD) that the intriguing luminescence changes are induced by the formation of new phases in C@YAG:Ce³⁺-1500 °C, which disappear in C@YAG:Ce³⁺-1650 °C. In order to understand the mechanisms responsible for the enhancement of YAG:Ce³⁺ emission and the presence of the blue emission observed for C@YAG:Ce³⁺-1500 °C, the samples have been investigated by a combination of several electron microscopy techniques, such as HRTEM, SEM-CL, and SEM-EDS. This local and cross-sectional analysis clearly reveals a gradual transformation of phase and morphology in heated C@YAG:Ce³⁺ phosphors, which is related to a reaction between C and YAG:Ce³⁺ in N₂ atmosphere. Through reaction between the carbon layer and YAG host materials, the emission colour of the phosphors can be modified from yellow, white, and then back to yellow under UV excitation as a function of heat-treatment in N₂ atmosphere.

Ce3+ and Tb3+ activated Ba3P4O13 phosphors based on energy transfer behavior

The energy transfer in Ba₃P₄O₁₃:Ce³⁺,Tb³⁺ was discussed and it shows excellent thermal stability.

Combinatorial optimization of the atomic compositions for green-emitting YBO3:Ce3+,Tb3+ and red-emitting YBO3:Ce3+,Tb3+,Eu3+ phosphors using a microplate reader

Compositions of green-emitting Y_1−x−yCexTbyBO₃ and red-emitting Y_{1−x−y−z}CexTbyEuzBO₃ were optimized by photoluminescence intensity of each microplate-well by using a microplate reader.

Size induced modification of boron structural unit in YBO3: systematic investigation by experimental and theoretical methods

Nanocrystalline YBO₃ (∼4–8 nm) was prepared using polyol method. It is established that while bulk YBO₃ has only BO₄ units, its nanoparticles has both BO₃ and BO₄ units. The BO₃ units are primarily distributed on surface on nanoparticles.

Photoluminescence properties and energy transfer of color tunable MgZn2(PO4)2:Ce3+,Tb3+ phosphors

Tunable blue to green novel MgZn₂(PO₄)₂:Ce³⁺,Tb³⁺ phosphors have been synthesized and investigated in detail.

Borohydride synthesis strategy to fabricate YBO3:Eu3+ nanophosphor with improved photoluminescence characteristics

Borohydride synthesized Eu³⁺-doped YBO₃ exhibited better color purity and chromaticity co-ordinates as compared to phosphors derived from the solid state route.