Photoluminescence features of trivalent holmium doped Ca2La8(SiO4)6O2 phosphors

This study examines the optical properties of Ca2La8-x(SiO4)(6)O-2:xHo(3+) phosphors derived using the sol-gel method. X-ray diffraction data and Rietveld analysis confirmed that the phosphors formed in hexagonal phase with an average estimated crystalline size of 27 nm. The prominent excitation peak observed at wavelength 463 nm corresponding to excitation energy 2.68 eV was due to the I-5(8) -> (5)G(6) + F-5(1) transition. The photoluminescence emission spectra revealed that the synthesized phosphors emitted in the green color region with the S-5(2) + F-5(4) -> I-5(8) transition, releasing 2.27 eV energy. The emission and excitation analyses revealed the presence of concentration quenching as the Ho3+ concentration exceeded 0.03 mol in the Ca2La8-x(SiO4)(6)O-2:xHo(3+) series. Further, photometry analysis demonstrated a color purity exceeding 94 %, which supports the candidacy of these phosphors for solid-state lighting applications.