Glass-ceramics with thermally stable blue-red emission for high-power horticultural LED applications

As one of the key elements for indoor agriculture, horticultural light sources are developing rapidly towards high energy density, high output power and high stability, which poses a challenge to traditional phosphor conversion devices. Grasping the nettle, all-inorganic blue-red dual-emitting light convertor consisting of Ba1.3Sr1.7MgSi2O8:Eu2+, Mn2+ (BSMS) phosphor in glass (PiG) plates were prepared to improve duration lifetime for high-power light-emitting diodes (LEDs) and meet the light quality requirements of photosynthesis for indoor agriculture. These obtained samples show an external quantum efficiency of 45.3%, outstanding thermal stability and specific emission spectrum that highly matched with the absorption of chlorophyll and β-carotene. Moreover, a proof-of-concept BSMS-PiG horticultural lamp for application in indoor plant factory was successfully fabricated base on ~370 nm emitting LED chip and the blue-red ratio of its spectrum was regulated by controlling the thickness of BSMS-PiG and the concentrations of Mn2+ ions in BSMS-PiG. The BSMS-PiG horticultural LEDs were applied in indoor cultivation of Romaine lettuce. The results indicated that biomass of Romaine lettuce was 58.21% greater than those cultivated under the light sources of commercial plant lamps. Especially, the content of total chlorophyll, β-carotene and soluble protein were improved. The BSMS-PiG horticultural LEDs is a potential candidate for high-power horticultural light source.