Narrow-band far red-emitting double-perovskite SrGd2Al2O7:Mn4+ phosphors

Abstract

Accurate light irradiation towards phytochrome has been considered as a key method to improve the efficiency of plant cultivation. In this work, a series of far red-emitting Mn 4+ -activated SrGd 2 Al 2 O 7 (SGAO) phosphors were synthesized by high temperature solid-state reaction. Under excitation at 330 nm, the optimized SGAO:0.1%Mn 4+ phosphor exhibits intense far-red emission in narrow range of 701–740 nm, which matches well with the absorption of phytochrome P FR and excludes from that of the phytochrome P R . Moreover, the SGAO:0.1%Mn 4+ sample exhibits considerable thermal quenching of far-red emission towards temperature, the emission intensity around 719 nm at 423 K was approximately 33% of that at room temperature. Also, the crystal field strength D q , the Racah parameters B and C, and the nephelauxetic ratio β 1 of SGAO: Mn 4+ were calculated and discussed. The results provide a reference for developing new high-efficient far-red-emitting phosphor towards indoor plant growth LEDs. • Narrow band far-red emission centered at 719nm can be observed in SrGd 2 Al 2 O 7 : Mn 4+ phosphors under exciting at 365nm. • The emission band matches well with the absorption of phytochrome P FR and excludes from that of the phytochrome P R . • The most intense far-red emission in SrGd 2 Al 2 O 7 :Mn 4+ phosphors occurs upon the situation of 0.1% Mn 4+ dopant. • SrGd 2 Al 2 O 7 :Mn 4+ shows the potential as a light-converter in the application of plant growth LEDs.