Dye doped concentric shell nanoparticles for enhanced photophysical performance of downconverting light emitting diodes

• Published in: Journal of colloid and interface science Vol. 556; no. C; pp. 753 - 760
• Main Authors: Ning, Xin, Chittigori, Joshna, Li, Ying, Horner, Glenn, Zhou, Zhe, Ullal, Chaitanya K., Schadler, Linda
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.11.2019; Elsevier
• Subjects: Downconverters; LED packaging; Optical properties; Perylene dye nanoparticles; Photoluminescence; Photostability; LED packaging; Perylene dye nanoparticles; Photostability; Optical properties; Downconverters; Photoluminescence
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2019.09.004

[Display omitted] •Designed dye doped SiO2 nanoparticles with novel concentric layered shell structure.•Mitigated the strong π-π aggregation tendency between perylene molecules.•Significantly enhanced photoluminescence and photostability with the optimized structure.•Strategy to improve optical performance of downconverting organic dye for LEDs. In this study, we examined the potential for perylene dye doped nanoparticles to enhance Light Emitting Diodes (LED) efficacy by minimizing π–π intermolecular aggregation, and enhancing photoluminescence and photostability of the dye molecules in the solid state. Towards this end, we encapsulated perylene dyes, suitably modified with a reactive silica precursor, into silica nanoparticles within a silica-dye-silica concentric layered shell. We found that the fluorescent yield was higher when the dye was embedded in a buried concentric shell within the silica nanoparticles (NPs) compared to an undoped shell/dye doped core nanoparticle morphology or unencapsulated dye with the same net dye concentration in solution. A strong dependence of relative quantum yield on dye doping concentration in the silica-dye-silica nanoparticles was observed. The uniform ∼ 100 nm large silica-dye-silica layered nanoparticles were used to prepare transparent dye doped silica nanoparticle/silicone nanocomposites. Dye doped silica nanoparticle/silicone nanocomposites exhibited higher photostability than the unencapsulated dye samples during long time aging tests under a blue LED with a wavelength of 455 nm at 300 ± 3% mA for 24 h. Novel dye doped layered silica NPs and their nanocomposites offer scope for developing organic luminescent materials into efficient and color-tunable light emitters for low-cost display, lighting, and optical communication applications.