High photoluminescence stability of CaGa4O7:Eu3+ red phosphor in wide excitation intensity interval

• The emission and excitation spectroscopy of CaGa4O7:Eu3+ compound are analyzed.
• Weak thermal quenching is shown in the temperature range of 10–300 K.
• The mechanisms responsible for photoluminescence decay formation are discussed.
• Constancy of emission efficiency in a wide excitation intensity range was obtained.

The photoluminescence (PL) of CaGa4O7 compound doped with Eu3+ ions is studied. It is shown that room temperature emission spectrum of CaGa4O7 compound consists of groups of lines in the red spectral region, caused by electronic transitions 5D0 → 7Fj (j = 1, 2, 3, 4) in Eu3+ ions with the most intensive lines at 612 nm and 615 nm. It is evaluated that low local symmetry of Eu3+ ion appears in the presence of several lines for each transitions. The PL decay constants were found to be in the range of 1.1–1.3 ms. Non-exponential rise was observed in the beginning of PL kinetics and assumed with energy transfer between Eu3+ ions in different sites in host lattice. Weak thermal quenching is shown in the temperature range of 10–300 K. Extreme stability of PL spectra and efficiency in a wide excitation intensity range of 104–108 W/cm2 were achieved. A slight emission efficiency reversible droop by only 25% is found to be at the excitation intensities from 2 · 107 W/cm2 to 108 W/cm2.