Greatly enhanced deep-red luminescence performance of Ca2InSbO6:Mn4+ phosphor via multiple optimization strategies

Abstract

Phosphors with high luminescence intensity, thermal stability, and spectral matching are important for indoor plant cultivation (IPC) light-emitting diodes (LEDs). Mn4+ ion-doped phosphors are considered potential deep-red emitters for plant growth LEDs. Herein, Ca2InSbO6:Mn4+ (CISO:Mn4+) phosphors were first synthesized via high-temperature solid-phase method. Their luminescence performance was greatly enhanced by using three kinds of strategies (charge compensator, solid solution, and rare earth ion co-doping). Furthermore, the optimization mechanisms were studied in depth on the basis of the principle of charge compensation and reduced quenching centers. Surprisingly, the internal quantum efficiency of the Ca1·9Y0·1InSb0·6Ta0·4O6:0.006Mn4+ phosphor was greatly enhanced to 71.4%, which was 42.75 times that of the CISO:0.006Mn4+ phosphor. Under 373 nm excitation, the Ca1·9Y0·1InSb0·6Ta0·4O6:0.006Mn4+ phosphor showed intense deep-red emission at 695 nm attributed to the 2Eg→4A2g transition of Mn4+ ions, which indicated a good match with far red phytochrome (Pfr, 84%). Finally, the fabricated IPC-LED displayed superior spectral matching, color purity (99.9%), and CIE chromaticity coordinates (0.692, 0.308). Thus, it has great potential as deep-red substitutes in the field of IPC. This work adopted a series of comprehensive strategies to optimize the luminescence performance of Mn4+-doped oxide phosphors and discussed the optimization mechanisms in depth, aiming to provide new ideas for the future optimization of phosphors.