Ce:YAG (Cerium-Doped Yttrium Aluminum Garnet) Single Crystal

Advantages

• Ultra-high quantum efficiency: Ce:YAG single crystals achieve internal quantum efficiencies up to 92% under blue excitation, enabling exceptional luminescence conversion efficiency.
• Fast luminescence decay: The Ce³⁺ 5d→4f transition exhibits a decay time of 60–100 ns, effectively preventing optical saturation at high excitation power densities.
• High thermal conductivity and stability: The YAG host provides thermal conductivity of ~10 W/(m·K), approximately 10 times that of conventional phosphor powders, with excellent lumen maintenance (97% at 200°C for single crystals).
• High saturation threshold under laser excitation: Single-crystal Ce:YAG demonstrates a luminescence saturation threshold of 12 W/mm² under 450 nm laser diode excitation, making it suitable for high-power laser lighting.
• Excellent scintillation performance: Light yield exceeding 20,000-30,000 photons/MeV with energy resolution of 14% (FWHM) at 662 keV, suitable for radiation detection applications.
• Non-hygroscopic and chemically inert: Superior environmental stability compared with hygroscopic scintillators such as CsI:Tl, enabling long-term operation without protective encapsulation.

Typical Specifications

• Chemical formula: Ce³⁺:Y₃Al₅O₁₂
• Crystal structure: Cubic garnet, space group Ia3d
• Lattice constant: a = 12.01 Å
• Ce doping concentration: 0.05–0.5 at.% (commonly 0.1–0.3 at.%)
• Absorption bands: 230 nm, 340 nm, 460 nm (Ce³⁺ 4f→5d transitions)
• Emission peak: ~540 nm (broad band, 500–700 nm)
• Emission transition: 5d → ⁴F₅/₂ and ⁴F₇/₂ of Ce³⁺
• Quantum efficiency: Up to 92% (internal QE)
• Decay time: 60–100 ns (scintillation); ~70 ns (photoluminescence)
• Light yield: 20,000–30,000 photons/MeV
• Energy resolution: 14% (FWHM, 662 keV)
• Density: 4.56 g/cm³
• Melting point: 1970 °C
• Mohs hardness: 8.5
• Thermal conductivity: ~10 W/(m·K)
• Refractive index: ~1.82

Standard Fabrication Specifications

• Growth method: Czochralski (CZ) method, along <111> direction in pure N₂ atmosphere
• Standard dimensions: 10 × 10 mm (square plates); thickness 0.15–0.45 mm
• Available forms: Single crystal plates, bulk crystals, and single crystal fibers
• Surface quality: 10/5 Scratch/Dig
• Surface flatness: λ/8 @ 632.8 nm
• Parallelism: ≤30 arc sec
• Coating: Customizable AR coatings for blue excitation and yellow emission

Main Applications

• High-power white laser lighting: Ce:YAG single crystals are the preferred phosphor conversion material for laser-driven white light sources, with demonstrated luminous efficacy of 274 lm/W and saturation threshold of 12 W/mm² . Applications include automotive headlights, stage lighting, and high-brightness projection systems.
• White LEDs and general illumination: Ce:YAG single crystal plates are used as phosphor converters in high-power white LEDs, offering superior thermal stability and longer lifetime than conventional powder phosphors .
• Scintillation detectors: Ce:YAG crystals are used for X-ray, γ-ray, and α-particle detection in nuclear physics, medical imaging (PET), and high-energy physics experiments. The fast decay time enables high-count-rate operation .
• Laser lighting systems: Single-crystal Ce:YAG combined with blue laser diodes enables ultra-bright, directional white light sources for specialized applications requiring high luminance.
• Composite phosphors (Ce:YAG/Al₂O₃): Composite single crystals incorporating Al₂O₃ inclusions offer enhanced thermal conductivity (~20 W/(m·K)) and light extraction efficiency, preferred for automotive and high-fluence laser lighting .
• Radiation monitoring: Ce:YAG scintillators are used for radiation dosimetry and environmental monitoring due to their high light yield and non-hygroscopic nature.