title: Far-field optical nanothermometry using individual sub-50 nm upconverting nanoparticles.
abstract: We demonstrate far-field optical thermometry using individual NaYF4 nanoparticles doped with 2% Er(3+) and 20% Yb(3+). Isolated 20 × 20 × 40 nm(3) particles were identified using only far-field optical imaging, confirmed by subsequent scanning electron microscopy. The luminescence thermometry response for five such single particles was characterized for temperatures from 300 K to 400 K. A standard Arrhenius model widely used for larger particles can still be accurately applied to these sub-50 nm particles, with good particle-to-particle uniformity (response coefficients exhibited standard deviations below 5%). With its spatial resolution on the order of 50 nm when imaging a single particle, far below the diffraction limit, this technique has potential applications for both fundamental thermal measurements and nanoscale metrology in industrial applications.
authors.affiliation: Department of Mechanical Engineering, University of California, Berkeley, California 94720, USA. cdames@berkeley.edu.
authors.forename: Jacob D
authors.initials: JD
authors.lastname: Kilbane
authors.affiliation: The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Emory M
authors.initials: EM
authors.lastname: Chan
authors.affiliation: Department of Mechanical Engineering, University of California, Berkeley, California 94720, USA. cdames@berkeley.edu and The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Christian
authors.initials: C
authors.lastname: Monachon
authors.affiliation: The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Borys
authors.affiliation: The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Levy
authors.affiliation: Department of Mechanical Engineering, University of California, Berkeley, California 94720, USA. cdames@berkeley.edu.
authors.forename: Andrea D
authors.initials: AD
authors.lastname: Pickel
authors.affiliation: The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Urban
authors.affiliation: The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: P James
authors.initials: PJ
authors.lastname: Schuck
authors.affiliation: Department of Mechanical Engineering, University of California, Berkeley, California 94720, USA. cdames@berkeley.edu and The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Chris
authors.initials: C
authors.lastname: Dames