A highly luminescent Mn4+ activated LaAlO3 far-red-emitting phosphor for plant growth LEDs: charge compensation induced Mn4+ incorporation

Abstract

As a potential far-red-emitting candidate for plant growth LEDs, Mn⁴⁺ activated oxide phosphors have brand-new application prospects. However, it remains a significant challenge to develop highly efficient far-red-emitting phosphors due to their intrinsic energy loss in a large Stokes shift. Herein, we present a rational charge compensation strategy with a fusible charge compensator MgF₂ at the molecular level to synthesize a LaAlO₃:Mn⁴⁺,Mg²⁺ far-red-emitting phosphor. Notably, MgF₂ can play an essential role in the incorporation of Mn⁴⁺ into the crystal matrix during the high-temperature solid-state reaction process, and thus induce a highly luminescent phosphor with a quantum yield of 78.6% and appropriate thermal stability. The fabrication of a high-performance far-red-emitting phosphor-converted LED further identifies the application potential of the modified Mn⁴⁺ activated LaAlO₃ phosphor. This finding sheds light on the further exploration of high-grade far-red phosphors.