Very stable and high-quantum-yield phosphor Na2BaSr(PO4)2:Eu2+ for plant growth LEDs

Controlling the light environment for plant growth using phosphor-converted light-emitting diodes (pc-LEDs) is an important means to regulate growth rhythm and enhance yield, for which bluish-violet light is one of the essential and important spectral components, particularly for plant photosynthesis. To reduce cost and improve the spectral matching between the cultivation pc-LEDs and the plant response spectrum, phosphors with excellent spectrum resemblance (SR), thermal stability and quantum yield (QY) are necessary for practical applications. A bluish-violet-emitting (428 nm) phosphor, Na2BaSr(PO4)(2):Eu2+ (NBSP:Eu2+), with extremely high QY of about 92% was developed, which not only well matches the absorption spectrum of chlorophyll-a (SRchlorophyll-a = 91.5%) in the blue region but also exhibits zero thermal quenching at the LED operating temperature (150 degrees C). The possible mechanism for its superior thermal stability was investigated and interpreted as the thermal ionization and recombination of Eu2+-5d with defect participation. Results indicated that NBSP:Eu2+ is a promising bluish-violet-emitting phosphor that possesses considerable potential application in plant growth LEDs.

Automated summary

Controlling plant growth environment with pc-LEDs is crucial for regulating growth rhythm and increasing yield. The developed phosphor NBSP:Eu2+ exhibits high quantum yield and excellent thermal stability in the blue-violet region, showing promising potential for application in plant growth LEDs.