title: Interaction of L-Cysteine with ZnO: Structure, Surface Chemistry, and Optical Properties.
abstract: Zinc oxide (ZnO) nanoparticles (NPs) were stabilized in water using the amino acid l-cysteine. A transparent dispersion was obtained with an agglomerate size on the level of the primary particles. The dispersion was characterized by dynamic light scattering (DLS), pH dependent zeta potential measurements, scanning transmission electron microscopy (STEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, photoluminescence (PL) spectroscopy, and X-ray absorption fine structure (EXAFS, XANES) spectroscopy. Cysteine acts as a source for sulfur to form a ZnS shell around the ZnO core and as a stabilizer for these core-shell NPs. A large effect on the photoluminescent properties is observed: the intensity of the defect luminescence (DL) emission decreases by more than 2 orders of magnitude, the intensity of the near band edge (NBE) emission increases by 20%, and the NBE wavelength decreases with increasing cysteine concentration corresponding to a blue shift of about 35 nm due to the Burstein-Moss effect.
authors.affiliation: †Nanoparticle Process Technology, ‡Interdisciplinary Center for Analytics on the Nanoscale, and CENIDEUniversity of Duisburg-Essen, Duisburg 47057, Germany.
authors.forename: Alice
authors.initials: A
authors.lastname: Sandmann
authors.affiliation: †Nanoparticle Process Technology, ‡Interdisciplinary Center for Analytics on the Nanoscale, and CENIDEUniversity of Duisburg-Essen, Duisburg 47057, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kompch
authors.affiliation: †Nanoparticle Process Technology, ‡Interdisciplinary Center for Analytics on the Nanoscale, and CENIDEUniversity of Duisburg-Essen, Duisburg 47057, Germany.
authors.forename: Viktor
authors.initials: V
authors.lastname: Mackert
authors.affiliation: †Nanoparticle Process Technology, ‡Interdisciplinary Center for Analytics on the Nanoscale, and CENIDEUniversity of Duisburg-Essen, Duisburg 47057, Germany.
authors.forename: Christian H
authors.initials: CH
authors.lastname: Liebscher
authors.affiliation: †Nanoparticle Process Technology, ‡Interdisciplinary Center for Analytics on the Nanoscale, and CENIDEUniversity of Duisburg-Essen, Duisburg 47057, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Winterer
mesh_terms: D003545:Cysteine / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D014961:X-Ray Diffraction; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D003545:Cysteine; D015034:Zinc Oxide