Phosphors Ba₂LaTaO₆:Mn⁴⁺ and its alkali metal charge compensation for plant growth illumination

Abstract A series of Mn 4+ ‐doped and Mn 4+ ,K + ‐co‐doped Ba 2 LaTaO 6 (BLT) double‐perovskite phosphors was synthesized using a high‐temperature solid‐state reaction. The phase purity and luminescence properties were also studied. The optimum doping concentration of Mn 4+ and K + was obtained by investigating the photoluminescence excitation spectra and photoluminescence emission spectra. The comparison of BLT:Mn 4+ phosphors with and without K + ions shows that the photoluminescence intensity of K + ‐doped phosphors was greatly enhanced. This is because there was a charge difference when Mn 4+ ions were doped with Ta 5+ ions in BLT. Mn 4+ –K + ion pairs were formed after doping K + ions, which hinders the nonradiative energy transfer between Mn 4+ ions. Therefore, the luminescence intensity, quantum yield, and thermal stability of phosphors were enhanced. The electroluminescence spectra of BLT:Mn 4+ and BLT:Mn 4+ ,K + were measured. The spectra showed that the light emitted from the phosphors corresponded well with chlorophyll a and phytochrome P R . The results show that the BLT:Mn 4+ ,K + phosphors had good luminescence properties and application prospects and are ideal materials for plant‐illuminated red phosphors.