Local Structure Modulation Induced Highly Efficient Far-Red Luminescence of La_{1- x}Lu _xAlO₃:Mn⁴⁺ for Plant Cultivation

Modulating the local environment around the emitting ions with component screening to increase the quantum yield and thermal stability is an effective and promising strategy for the design of high-performance fluorescence materials. In this work, smaller Lu³⁺ was introduced into the La³⁺ site in a Mn⁴⁺-activated LaAlO₃ phosphor with the expectation of improving the luminescence properties via lattice contraction induced by cation substitution. Finally, a La_{1- x}Lu _xAlO₃:Mn⁴⁺ ( x = 0-0.04) perovskite phosphor with a high quantum yield of 86.0% and satisfactory thermal stability was achieved, and the emission peak at 729 nm well matches with the strongest absorption peak of the Phytochrome P_FR. The favorable performances could be attributed to the suppressed cell volume and superior lattice rigidity after the substitution of Lu³⁺. This work not only obtains a highly efficient La_{1- x}Lu _xAlO₃:Mn⁴⁺ ( x = 0.02) phosphor, which holds great potential for application in plant-cultivation light-emitting diodes, but also provides an applicable strategy for further investigation of far-red-emitting phosphors.