(La_0.97RE_0.01Yb_0.02)₂O₂S Nanophosphors Converted from Layered Hydroxyl Sulfate and Investigation of Upconversion Photoluminescence (RE=Ho, Er).

ABSTRACT: Phase-pure (La_0.97RE_0.01Yb_0.02)₂O₂S upconversion (UC) nanophosphors (average crystallite size ~ 45 nm; RE=Ho, Er) were annealed from their hydrothermally crystallized layered hydroxyl sulfate precursors in flowing hydrogen at 1200 °C for 1 h, with water vapor as the only exhaust. Under 978-nm laser excitation (up to 2.0 W), the Ho³⁺-doped phosphor exhibited green (medium), red (weak), and near-infrared (strong) emissions at ~ 546 (⁵F₄ → ⁵I₈), 658 (⁵F₇ → ⁵I₈), and 763 nm (⁵F₄ → ⁵I₇), respectively, and has the stable chromaticity coordinates of about (0.30, 0.66) in the visible-light region (400-7

SUBMITTER: Li JG 

PROVIDER: S-EPMC5570760 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature