title: High-quality manganese-doped zinc sulfide quantum rods with tunable dual-color and multiphoton emissions.
abstract: We report a simple, fast and green phosphine-free colloidal chemistry to synthesize high-quality wurtzite-type Mn-doped ZnS quantum rods (QRs) with tunable diameters (1.6-5.6 nm), high aspect ratios (up to 50), variable Mn doping levels (0.18-1.60%), and high quantum yields (up to 45%). The electron paramagnetic resonance spectra with modeling reveal the successful doping of paramagnetic Mn(2+) ions in the host ZnS QRs. The Mn-doped ZnS QRs demonstrate tunable dual-color (orange and blue) emissions by tuning the doping levels and UV excitation wavelengths. The orange emission with long decay lifetime (3.3 ms) originates from the doped Mn(2+) states, while the blue emission with fast decay lifetime (0.31 ns) is attributed to the QR surface states. The bright two- and three-photon excitation upconversion luminescence from the Mn-doped ZnS QRs have been observed using tunable near-infrared femtosecond laser. Our strategy provides a versatile route to programmably control the optical properties of anisotropic semiconductor nanomaterials, which may create new opportunities for photonic devices and bioimaging applications.
authors.affiliation: The Biodesign Institute, Arizona State University, Tempe, Arizona 85287, USA.
authors.forename: Zhengtao
authors.initials: Z
authors.lastname: Deng
authors.forename: Ling
authors.initials: L
authors.lastname: Tong
authors.forename: Marco
authors.initials: M
authors.lastname: Flores
authors.forename: Su
authors.initials: S
authors.lastname: Lin
authors.forename: Ji-Xin
authors.initials: JX
authors.lastname: Cheng
authors.forename: Hao
authors.initials: H
authors.lastname: Yan
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
mesh_terms: D003116:Color; D008163:Luminescent Measurements; D008345:Manganese / Q000737:chemistry*; D055620:Optical Phenomena; D017785:Photons; D013440:Sulfides / Q000737:chemistry*; D017967:Zinc Compounds / Q000737:chemistry*
chemical_list: D013440:Sulfides; D017967:Zinc Compounds; D008345:Manganese; C031238:zinc sulfide