Synthesis and photoluminescence properties of novel red-emitting phosphor SrAl3BO7:Mn4+ with enhanced emission by Mg2+/Zn2+/Ca2+ incorporation for plant growth LED lighting

摘要

Indoor cultivation has attracted more and more concerns in the last few years. Searching for ideal red-emitting phosphors for this application has been a great challenge. In this paper, a novel red-emitting phosphor SrAl3BO7:Mn4+ (SABO:Mn4+) had been synthesized through a modified hydrothermal reaction method for the first time. Three kinds of effect parameters, including hydrothermal reacting time, sintering temperature and Mn4+ doping concentration, were comprehensively considered to optimize the phase purity and luminescent properties of the SABO:Mn4+ phosphor. Besides, the luminescent properties of SABO:Mn4+ was systematically investigated through UV-vis absorption spectra, PLE and PL spectra, CIE chromaticity coordinate and decay times. The excitation band of this phosphor locates in the wavelength range of 250-550 nm, resulting from Mn4+ -> O(2- )charge transfer and electron transitions from (4)A(2)-T-4(1), T-2(2) and T-4(2) energy levels. Meanwhile, a sharp emission band is detected from 600 to 700 nm with two emission peaks located at 648 and 662 nm, which is assigned to E-2 -> (4)A(2) characteristic transition of Mn4+. In addition, Mg2+/Zn2+/Ca2+ are co-doped as charge compensators to improve the luminescent properties of SABO:0.03Mn(4+). The impacts of doping concentration of Mg2+/Zn2+/Ca2+ on the photoluminescent intensity, QE and thermal stability of SABO:0.03Mn(4+) phosphor is investigated carefully. The corresponding mechanism is discussed via decay times, EPR spectra and configurational coordinated diagram. More importantly, the EL spectrum of as-fabricated pc-LED device matches well with the absorption of plant pigments, demonstrating this novel phosphor can regard as a promising red-emitting luminescent material to meet the light requirement in plant growth LED lighting.