Ca 2 LaTaO 6 :Bi 3+ /Mn 4+ Phosphors with High Brightness Far-Red Emitting and Luminescence Enhancement for Plant Growth LED Lights and Temperature Sensor.

Herein, Bi 3+ /Mn 4+ doped Ca 2 LaTaO 6 phosphors with a double-perovskite structure were successfully synthesized with solid-state reaction at high temperature. The photoluminescence (PL) performances were investigated in detail. The blue radiation (∼465 nm) from the Bi 3+ ion and the red radiation (∼686 nm) originating from the Mn 4+ ion were obtained under 313 nm excitation. Especially, the pathway of energy transfer (Bi 3+ → Mn 4+ ) contributes to enhance the red emission intensity (Mn 4+ : ∼686 nm) in Ca 2 LaTaO 6 :Bi 3+ /Mn 4+ system. The PL mechanism of Ca 2 LaTaO 6 :Bi 3+ /Mn 4+ was analyzed through luminescence lifetimes and PL spectra. Moreover, the emitting bands of Ca 2 LaTaO 6 :Bi 3+ /Mn 4+ were primarily matched with the absorbing bands of carotenoids and phytochrome P FR on behalf of plant growth, so the phosphors were suitable for the design of a plant growth light under near-ultraviolet to blue excitation. At last, the optical temperature dependent performances of the Ca 2 LaTaO 6 :Bi 3+ /Mn 4+ were analyzed with luminescence intensity ratio technology. The sample has presented excellent temperature measuring relative sensitivity ( S R = 2.106% K -1 ). The results illustrated that the Ca 2 LaTaO 6 :Bi 3+ /Mn 4+ phosphor also can be used to develop an optical temperature sensor.