Sm³⁺ Activated Potassium Magnesium Pyrophosphate Nanophosphor: Synthesis, Structure, Optical and Luminescence Studies

Area of Science:

• Materials Science
• Solid-State Chemistry
• Luminescence

Background:

• Development of efficient luminous materials is crucial for advanced lighting technologies.
• Samarium (Sm³⁺) ions are known for their characteristic emission properties.
• Pyrophosphate (P₂O₇)⁴⁻ based materials offer tunable optical characteristics.

Purpose of the Study:

• Synthesize novel K₂Mg(₁₋ₓ)SmₓP₂O₇ nanophosphors.
• Investigate their structural, morphological, and optical properties.
• Evaluate their potential for white light-emitting diode (WLED) applications.

Main Methods:

• Self-propagating solution combustion synthesis.
• X-ray Diffraction (XRD) for structure validation.
• Fourier Transform Infrared Spectroscopy (FTIR) for functional group identification.
• High-Resolution Transmission Electron Microscopy (HRTEM) for morphology.
• X-ray Photoelectron Spectroscopy (XPS) for electronic structure.
• Diffuse Reflectance Spectroscopy (DRS) for optical bandgap determination.
• Photoluminescence (PL) spectroscopy for emission characteristics.
• Photometric investigations for color properties.

Main Results:

• Single-phase K₂Mg(₁₋ₓ)SmₓP₂O₇ nanophosphors were successfully synthesized.
• FTIR confirmed the presence of the pyrophosphate group.
• HRTEM and XPS provided insights into morphology and electronic states.
• PL spectroscopy revealed a characteristic emission peak at 603 nm (⁴G₅/₂ → ⁶H₇/₂ transition of Sm³⁺) upon excitation at 402 nm.
• Optimized phosphors exhibited 87% color purity, a correlated color temperature (CCT) of 1768 K, and CIE coordinates (x=0.58, y=0.42).

Conclusions:

• The synthesized K₂Mg(₁₋ₓ)SmₓP₂O₇ nanophosphors exhibit efficient amber emission.
• Their properties make them suitable candidates for solid-state lighting, particularly in WLEDs.
• The study highlights the potential of pyrophosphate-based materials doped with Sm³⁺ for lighting applications.