Plasmonic enhancement of upconversion emission in Ag@NaYF₄:Er³⁺/Yb³⁺ phosphor

S.K.Maurya，S.P.Tiwari，A.Kumar，K.Kumar

Optical Materials and Bio-imaging Research Laboratory,Department of Applied Physics,Indian Institute of Technology (Indian School of Mines)

摘 要：In this article upconversion luminescence of silver nanoparticles（AgNPs） coated NaYF₄:Er³⁺/Yb³⁺phosphor nano-particles was investigated.The prepared samples were characterized through various techniques.The surface plasmon band is observed for prepared AgNPs by analyzing UV-vis measurements and is used to enhance the upconversion emission.From the upconversion measurement the emission bands are observed at 522,546,and 656 nm corresponding to the ² H_11/2→ 4¹_15/2,⁴ S_3/2→⁴ I_15/2and ⁴ F_9/2→⁴ I_15/2 levels,respectively.The upconversion emission intensity of the above bands is found to enhance for sample containing 1 mmol AgNPs.Decay time of ⁴ S_3/2 and 4^F_9/2 levels is found to decrease on coating of AgNPs and hence intensity enhancement is assumed due to the surface plasmon resonance（SPR） effect.

关键词：