title: Controlling upconversion nanocrystals for emerging applications.
abstract: Lanthanide-doped upconversion nanocrystals enable anti-Stokes emission with pump intensities several orders of magnitude lower than required by conventional nonlinear optical techniques. Their exceptional properties, namely large anti-Stokes shifts, sharp emission spectra and long excited-state lifetimes, have led to a diversity of applications. Here, we review upconversion nanocrystals from the perspective of fundamental concepts and examine the technical challenges in relation to emission colour tuning and luminescence enhancement. In particular, we highlight the advances in functionalization strategies that enable the broad utility of upconversion nanocrystals for multimodal imaging, cancer therapy, volumetric displays and photonics.
authors.affiliation: Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, 117602 Singapore, Singapore.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhou
authors.affiliation: Advanced Cytometry Labs, ARC Centre of Excellence for Nanoscale BioPhotonics, Macquarie University, Sydney, New South Wales 2109, Australia.
authors.forename: Bingyang
authors.initials: B
authors.lastname: Shi
authors.affiliation: Advanced Cytometry Labs, ARC Centre of Excellence for Nanoscale BioPhotonics, Macquarie University, Sydney, New South Wales 2109, Australia.|Institute for Biomedical Materials and Devices, Faculty of Science, University of Technology Sydney, New South Wales 2007, Australia.
authors.forename: Dayong
authors.identifier: http://orcid.org/0000-0003-1046-2666
authors.initials: D
authors.lastname: Jin
authors.affiliation: Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, 117602 Singapore, Singapore.|Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543 Singapore, Singapore.|Centre for Functional Materials, NUS (Suzhou) Research Institute, Suzhou, Jiangsu 215123, China.
authors.forename: Xiaogang
authors.identifier: http://orcid.org/0000-0003-2517-5790
authors.initials: X
authors.lastname: Liu
mesh_terms: D000818:Animals; D006801:Humans; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D049408:Luminescent Agents / Q000737:chemistry*; D008163:Luminescent Measurements; D008958:Models, Molecular; D064847:Multimodal Imaging; D050997:Nanomedicine; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology; D009369:Neoplasms / Q000175:diagnosis / Q000628:therapy; D061848:Optical Imaging; D055095:Optics and Photonics
chemical_list: D028581:Lanthanoid Series Elements; D049408:Luminescent Agents