Photoluminescence and Cathodoluminescence Properties of Nanocrystalline <scp> <scp> Ca ₂ Gd ₈ Si ₆ O ₂₆ </scp> </scp> : <scp> <scp> Sm ³⁺ </scp> </scp> Phosphors

Abstract

Nanocrystalline Ca 2 Gd 8 Si 6 O 26 ( CGS ): Sm 3+ phosphors were synthesized by solvothermal reaction method. The structural and morphological properties of the samples were evaluated by X‐ray diffraction and scanning electron microscopy. The photoluminescence excitation and emission spectra along with decay properties were investigated as a function of Sm 3+ concentration. Under 405 nm excitation wavelength, the photoluminescence spectra showed three emission peaks at 565 nm ( 4 G 5/2 → 6 H 5/2 ) and at 650 nm ( 4 G 5/2 → 6 H 9/2 ), and with an intense orange emission at 600 nm ( 4 G 5/2 → 6 H 7/2 ) . Based on the orange emission performance, the Sm 3+ concentration was optimized to be at 2 mol%. The low voltage cathodoluminescence ( CL ) properties were also performed for 2 mol% Sm 3+ ‐doped CGS phosphors as a function of accelerating voltage (1–5 kV). From the CL spectra, the reddish‐orange emission was observed. The calculated Commission International De I‐Eclairage chromaticity coordinates are in close proximity to the chromaticity coordinates of Nichia corporation developed amber light emitting diodes.