Near-infrared Quantum Cutting Enhancement In NaYF₄:Er³⁺ Nanoparticles By Double Plasmon Modes Of Noble Metals

In this paper,the two-photon near-infrared?NIR?quantum cutting?QC?luminescence properties of NaYF₄:Er³⁺nanoparticles?NPs?are studied.Plasmon-enhanced NIR QC luminescence of NaYF₄:Er³⁺NPs is realized by double plasmon modes of noble metals.The rate equations of NIR QC are established and the electric field distribution around noble metal NPs is simulated by finite-difference time-domain?FDTD?method to analyze the mechanism of plasmon-enhanced NIR QC luminescence.The results of this study have potential applications for improving the photoelectric conversion efficiency of silicon-based solar cells.The contents of this paper are as follows:Firstly,NaYF₄:Er³⁺NPs are prepared by the co-precipitation method.The excitation and emission spectra of NaYF₄:Er³⁺NPs are measured,and the results show that the optimal doping concentration of Er³⁺ion is 4%.The QC luminescence properties of NaYF₄:Er³⁺NPs under the excitation of 486 nm are studied,and the energy transfer?ET?mechanism between Er³⁺ions is proved to be cross-relaxation ET.Secondly,Ag nanocubes?NCs?and Au nanorods?NRs?are prepared by the chemical reduction method and seed-mediated method,respectively.Then,the NaYF₄:Er³⁺NPs are decorated with Ag NCs and Au NRs simultaneously.Plasmon-enhanced NIR QC luminescence of NaYF₄:Er³⁺NPs is obtained by the localized surface plasmons resonance?LSPR?of Ag NCs and Au NRs.The effect of Ag NCs and Au NRs on NIR QC luminescence is investigated.The results show that the optimal concentration of Au NRs is 0.225%and Ag NCs is 0.06%with the maximum NIR QC luminescence enhancement factor about 3.5.Combined on Judd-Ofelt?J-O?theory and FDTD method,the rate equations of NIR QC are utilized to analyze the NIR QC luminescence enhancement mechanism.Lastly,Au@Ag core-shell NPs are prepared by the chemical reduction method.Then,the NaYF₄:Er³⁺NPs are decorated with Au@Ag core-shell NPs.The double plasmon modes of Au@Ag core-shell NPs are utilized to realize the excitation efficiency enhancement and emission rate enhancement of NIR QC luminescence of NaYF₄:Er³⁺NPs,simultaneously.The effect of double plasmon modes of Au@Ag core-shell NPs on NIR QC luminescence is investigated.The results show that the optimal concentration of Au@Ag core-shell NPs is 0.15%with the maximum NIR QC luminescence enhancement factor about 4.27.Moreover,the NIR QC luminescence enhancement mechanism is analyzed.