title: Unoccupied states in Cu and Zn octaethyl-porphyrin and phthalocyanine.
abstract: Copper and zinc phthalocyanines and porphyrins are used in organic light emitting diodes and dye-sensitized solar cells. Using near edge x-ray absorption fine structure (NEXAFS) spectroscopy at the Cu 2p and Zn 2p edges, the unoccupied valence states at the Cu and Zn atoms are probed and decomposed into 3d and 4s contributions with the help of density functional calculations. A comparison with the N 1s edge provides the 2p states of the N atoms surrounding the metal, and a comparison with inverse photoemission provides a combined density of states.
authors.affiliation: Physics Department, University of Wisconsin Madison, 1150 University Ave., Madison, Wisconsin 53706, USA.
authors.forename: Peter L
authors.initials: PL
authors.lastname: Cook
authors.forename: Wanli
authors.initials: W
authors.lastname: Yang
authors.forename: Xiaosong
authors.initials: X
authors.lastname: Liu
authors.forename: Juan María
authors.initials: JM
authors.lastname: García-Lastra
authors.forename: Angel
authors.initials: A
authors.lastname: Rubio
authors.forename: F J
authors.initials: FJ
authors.lastname: Himpsel
mesh_terms: D003300:Copper / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D054833:Isoindoles; D008665:Metalloporphyrins / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D011789:Quantum Theory; D013237:Stereoisomerism; D015032:Zinc / Q000737:chemistry*
chemical_list: D007211:Indoles; D054833:Isoindoles; D008665:Metalloporphyrins; D009942:Organometallic Compounds; D003300:Copper; D015032:Zinc; C013647:phthalocyanine