title: Hybrid Molecule-Nanocrystal Photon Upconversion Across the Visible and Near-Infrared.
abstract: The ability to upconvert two low energy photons into one high energy photon has potential applications in solar energy, biological imaging, and data storage. In this Letter, CdSe and PbSe semiconductor nanocrystals are combined with molecular emitters (diphenylanthracene and rubrene) to upconvert photons in both the visible and the near-infrared spectral regions. Absorption of low energy photons by the nanocrystals is followed by energy transfer to the molecular triplet states, which then undergo triplet-triplet annihilation to create high energy singlet states that emit upconverted light. By using conjugated organic ligands on the CdSe nanocrystals to form an energy cascade, the upconversion process could be enhanced by up to 3 orders of magnitude. The use of different combinations of nanocrystals and emitters shows that this platform has great flexibility in the choice of both excitation and emission wavelengths.
authors.affiliation: Department of Chemistry University of California Riverside, Riverside California 92521, United States.
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Department of Chemistry University of California Riverside, Riverside California 92521, United States.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Chemistry University of California Riverside, Riverside California 92521, United States.
authors.forename: Melika
authors.initials: M
authors.lastname: Mahboub
authors.affiliation: Department of Chemistry University of California Riverside, Riverside California 92521, United States.
authors.forename: Kerry M
authors.initials: KM
authors.lastname: Hanson
authors.affiliation: Department of Chemistry University of California Riverside, Riverside California 92521, United States.
authors.forename: Valerie M
authors.initials: VM
authors.lastname: Nichols
authors.affiliation: Department of Chemistry University of California Riverside, Riverside California 92521, United States.
authors.forename: Hoang
authors.initials: H
authors.lastname: Le
authors.affiliation: Department of Chemistry University of California Riverside, Riverside California 92521, United States.
authors.forename: Ming L
authors.initials: ML
authors.lastname: Tang
authors.affiliation: Department of Chemistry University of California Riverside, Riverside California 92521, United States.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Bardeen
mesh_terms: D000873:Anthracenes / Q000737:chemistry*; D019187:Cadmium Compounds / Q000737:chemistry*; D007854:Lead / Q000737:chemistry*; D008027:Light; D049449:Luminescence; D009279:Naphthacenes / Q000737:chemistry*; D017785:Photons; D045663:Quantum Dots / Q000737:chemistry*; D018036:Selenium Compounds / Q000737:chemistry*; D012993:Solar Energy
chemical_list: D000873:Anthracenes; D019187:Cadmium Compounds; D009279:Naphthacenes; D018036:Selenium Compounds; C088065:lead selenide; D007854:Lead; C045049:rubrene; C046961:9,10-diphenylanthracene; C058667:cadmium selenide
keywords: Triplet; acenes; hybrid; nanocrystals; solar; upconversion