High-Performance Simultaneous Two-Photon Absorption Upconverted Stimulated Single-Component Sr2V2O7 Phosphor for White LEDs

Abstract

Notwithstanding the wide use of white light-emitting diodes (w-LEDs), conventionally consisting of multiple emitting components, some inevitable issues still exist nowadays, such as the intrinsic color balance, device complexity, and high cost associated with such multiple emitting components. We have synthesized simultaneous two-photon absorption upconverted stimulated single-component Sr2V2O7 phosphor for use in w-LEDs. Due to the photon avalanche upconversion, the as-grown phosphor exhibits an enhanced photoluminescence spectrum in the range of 400 nm to 650 nm for white light when excited by red light at 693 nm. Moreover, when evenly dispersed in polyethylene glycol dispersant, the as-grown phosphor simultaneously produced strong visible white light when using an excitation wavelength λex of 693 nm, suggesting a possible route to produce w-LEDs by using red chips as an excellent substitute for traditional w-LEDs with multiple emitting components based on rare-earth metals. Finally, density functional calculations were performed using the generalized gradient approximation to study the electronic structure of Sr2V2O7 crystal. A reasonable model is proposed to explain the two-photon absorption luminescence mechanism.