Zero-thermal-quenching of Mn4+ far-red-emitting in LaAlO3 perovskite phosphor via energy compensation of electrons' traps

Nowadays, Mn4+-doped oxide phosphors have attracted more and more attentions owing to their widespread applications in white LEDs, optical data storage and agricultural production, but these phosphors have two most significant problems including thermal quenching (TQ) and low quantum efficiency. Here, we report a far-red-emitting LaAlO3:3%Ca2+,1%Bi3+,0.1%Mn4+ perovskite phosphor which exhibits zero-TQ even up to 150 degrees C and high internal quantum efficiency (IQE) of 89.3%. To our best knowledge, the zero-TQ phenomenon is first realized in Mn4+-activated perovskite phosphors caused by the synergistic action of Ca2+ and Bi3+ which is attributed to the efficient energy transfer, energy compensation and structural rigidity enhancement. Moreover, the gratifying luminous performance improvement is obtained due to charge compensation effect, optimized crystal field and excited electrons transfer. The main emission peak of this phosphor is monitored at similar to 730 nm which perfectly matches the absorption spectrum of phytochrome P-FR which has a good application prospect for improving plant seed germination, flowering, fruiting and aging. These findings may provide a feasible way to simultaneously improve thermal stability and quantum efficiency of Mn4+ luminescence in oxide hosts.