Self-Activated Green-Yellow Emitting Gd₂CaZnO5 Phosphor for Efficient Ultra-Violet Light-Emitting Diodes
Naina Lohia1, Savvi Mishra1, Swati Bishnoi1
1Council of Scientific and Industrial Research-National Physical Laboratory (CSIR-NPL), Dr. K. S. Krishnan Road, New Delhi 110012, India.
Journal of Nanoscience and Nanotechnology
|November 22, 2019
Summary
A novel green-yellow emitting phosphor, Gd₂CaZnO₅ (GCZO), was synthesized for UV-LED applications. This material exhibits promising properties for warm white light-emitting diodes (LEDs).
Area of Science:
- Materials Science
- Solid-State Chemistry
- Luminescence
Background:
- Development of efficient phosphors is crucial for advanced lighting technologies.
- Green-yellow emitting materials are sought after for white light-emitting diode (LED) applications.
Purpose of the Study:
- To synthesize and characterize a novel self-activated green-yellow emitting phosphor, Gd₂CaZnO₅ (GCZO).
- To evaluate the suitability of GCZO for UV-LED excited white-LED applications.
Main Methods:
- Solid-state reaction method at high temperature for phosphor synthesis.
- X-ray Diffraction (XRD) for structural analysis.
- Scanning Electron Microscopy (SEM) for morphology.
- Photoluminescence (PL) spectroscopy for optical properties.
Main Results:
- Synthesized Gd₂CaZnO₅ (GCZO) exhibits an orthorhombic structure (Pbnm space group).
- Broad green-yellow emission centered at 530 nm upon UV excitation (~377 nm), attributed to defects and oxygen vacancies.
- Calculated color coordinates (x, y) = (0.44, 0.45) and correlated color temperature of 3289 K, indicating warm white light emission.
Conclusions:
- The synthesized GCZO phosphor demonstrates efficient green-yellow luminescence.
- Its optical properties, including color coordinates, support its application in warm white LEDs.
- GCZO is a promising candidate for UV-LED excited white-LED applications.
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