title: Enhancing the upconversion luminescence and photothermal conversion properties of ∼800nm excitable core/shell nanoparticles by dye molecule sensitization.
abstract: Upconversion nanoparticles capable of strongly absorbing photons in a wide spectral range are highly desired for practical applications. In this work, IR-806 dye was used to increase the light absorptivity of Nd3+/Yb3+/Er3+tri-doped core/shell nanoparticles and then to enhance their upconversion luminescence under ∼800nm excitation. The IR-806 dye exhibited more efficient energy transfer to Nd3+ions than to Yb3+ions for subsequent upconversion emission due to the increased spectral overlap between the dye emission and Nd3+absorption. The influence of the Nd3+concentration in the shell and the dye/nanoparticle ratio on the dye-sensitization effect was also investigated. A maximum 28-fold overall enhancement in the emission intensity was achieved for NaYF4:Yb3+/Er3+@NaYF4:Yb3+/Nd3+core/shell nanoparticles using dye sensitization. The dye-sensitized NaYF4:Yb3+/Er3+@NaYF4:Yb3+/Nd3+core/shell nanoparticles also exhibited increased photothermal conversion capabilities and excellent temperature sensing properties, enabling their potential application in photothermal nanoheaters with real-time temperature monitoring under 808nm single beam excitation.
authors.affiliation: School of Materials Science and Engineering, Jiangsu Key Laboratory for Advanced Metallic Materials, Southeast University, Nanjing 211189, PR China. Electronic address: qiyueshao@seu.edu.cn.
authors.forename: Qiyue
authors.initials: Q
authors.lastname: Shao
authors.affiliation: School of Materials Science and Engineering, Jiangsu Key Laboratory for Advanced Metallic Materials, Southeast University, Nanjing 211189, PR China.
authors.forename: Xiaosong
authors.initials: X
authors.lastname: Li
authors.affiliation: School of Materials Science and Engineering, Jiangsu Key Laboratory for Advanced Metallic Materials, Southeast University, Nanjing 211189, PR China.
authors.forename: Peiyi
authors.initials: P
authors.lastname: Hua
authors.affiliation: School of Materials Science and Engineering, Jiangsu Key Laboratory for Advanced Metallic Materials, Southeast University, Nanjing 211189, PR China.
authors.forename: Gongtuo
authors.initials: G
authors.lastname: Zhang
authors.affiliation: School of Materials Science and Engineering, Jiangsu Key Laboratory for Advanced Metallic Materials, Southeast University, Nanjing 211189, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Dong
authors.affiliation: School of Materials Science and Engineering, Jiangsu Key Laboratory for Advanced Metallic Materials, Southeast University, Nanjing 211189, PR China.
authors.forename: Jianqing
authors.initials: J
authors.lastname: Jiang
keywords: Dye sensitization; Photothermal conversion; Temperature sensing; Upconversion nanoparticles