title: Hydrothermal synthesis of high-quality type-II CdTe/CdSe quantum dots with near-infrared fluorescence.
abstract: A simple hydrothermal method is developed for the synthesis of high-quality, water-soluble, and near-infrared (NIR)-emitting type-II core/shell CdTe/CdSe quantum dots (QDs) by employing thiol-capped CdTe QDs as core templates and CdCl(2) and Na(2)SeO(3) as shell precursors. Compared with the original CdTe core QDs, the core/shell CdTe/CdSe QDs exhibit an obvious red-shifted emission, whose color can be tuned between visible and NIR regions (620-740 nm) by controlling the thickness of the CdSe shell. The photoluminescence quantum yield (PL QY) of CdTe/CdSe QDs with an optimized thickness of the CdSe shell can reach up to 44.2% without any post-preparative treatment. Through a thorough study of the core/shell structure by high-resolution transmission electron microscopy (HRTEM), ultraviolet-visible (UV-vis) absorption spectra, fluorescence spectra, X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), the as-prepared CdTe/CdSe QDs demonstrate good monodispersity, hardened lattice structure and excellent photostability, offering a great potential for biological application.
authors.affiliation: College of Science, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Heyou
authors.initials: H
authors.lastname: Han
mesh_terms: D019187:Cadmium Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010316:Particle Size; D045663:Quantum Dots; D011789:Quantum Theory; D018036:Selenium Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D019265:Spectroscopy, Near-Infrared; D013499:Surface Properties; D013691:Tellurium / Q000737:chemistry; D013696:Temperature
chemical_list: D019187:Cadmium Compounds; D018036:Selenium Compounds; C058667:cadmium selenide; D013691:Tellurium; C028337:cadmium telluride