Towards control facilities for mimicking plant growth optimum action spectrum: Efficient near-ultraviolet to far-red light-conversion in Cr3+-doped rare-earth aluminate phosphors

Phosphor-converted materials have recently become promising candidates for the next generation horticulture and agriculture owing to their ability to overcome the daily sunlight limitations. Here, Tb0.7La0.3ZnAl11O19:Cr3+ (TLZA:Cr3+) was prepared by a high-temperature solid state method, which showed high near-ultraviolet (NUV) and green light to far-red conversion efficiencies. In the optimized TLZA:6%Cr3+ phosphor, the energy transfer from the host to the dopant was carried out through a dipole-quadrupole interaction mechanism with an efficiency of 99.62 %. The phosphor-converted light-emitting diode (pc-LED) devices were fabricated by combining TLZA:6%Cr3+, blue and red phosphors with 380 nm NUV-chips, which modulated the optimum action spectrum for indoor plant growth. TLZA:6%Cr3+ luminescent film laminated glass (LFLG) adjusted the composition of the solar spectrum to red/blue light ratio of 3:1 and promoted plant growth in outdoor horticultural greenhouses. Therefore, the pc-LED and LFLG fabricated with the TLZA:6%Cr3+ phosphor in this work are excellent spectral control devices for indoor plant lighting and outdoor horticultural facilities, respectively.