TY - JOUR
T1 - Quasi-one-dimensional K-O Chain in PTCDA thin films
T2 - Evidence from first-principles calculations
AU - Zazza, Costantino
AU - Meloni, Simone
AU - Palma, Amedeo
AU - Knupfer, Martin
AU - Fuentes, Gonzalo G.
AU - Car, Roberto
PY - 2007
Y1 - 2007
N2 - Using density functional theory calculations we have found that K atoms in a PTCDA (3,4:9,10-perylenetetracarboxylic dianhydride) crystal form a quasi-one-dimensional (1D) K-O chain interacting with carboxylic oxygen of the terminal anhydride groups of PTCDA. The K-K distance in the chain (3.72...) is commensurate to the periodicity of the organic semiconductor. We obtain that the K-O structure is stabilized by charge transfer from K to PTCDA molecules, forming prevalently ionic bonds: the electronic density of the chemistry induced gap states is essentially delocalized on the perylene core of PTCDA, while potassium appears spoiled of its charge. Band dispersion along the direction of molecular stack is evaluated to be 0.2 eV in pure PTCDA crystal and 0.5 eV in the K-doped system, confirming that the interaction occurs between different molecular planes.
AB - Using density functional theory calculations we have found that K atoms in a PTCDA (3,4:9,10-perylenetetracarboxylic dianhydride) crystal form a quasi-one-dimensional (1D) K-O chain interacting with carboxylic oxygen of the terminal anhydride groups of PTCDA. The K-K distance in the chain (3.72...) is commensurate to the periodicity of the organic semiconductor. We obtain that the K-O structure is stabilized by charge transfer from K to PTCDA molecules, forming prevalently ionic bonds: the electronic density of the chemistry induced gap states is essentially delocalized on the perylene core of PTCDA, while potassium appears spoiled of its charge. Band dispersion along the direction of molecular stack is evaluated to be 0.2 eV in pure PTCDA crystal and 0.5 eV in the K-doped system, confirming that the interaction occurs between different molecular planes.
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U2 - 10.1103/PhysRevLett.98.046401
DO - 10.1103/PhysRevLett.98.046401
M3 - Article
C2 - 17358791
AN - SCOPUS:33846556798
SN - 0031-9007
VL - 98
JO - Physical review letters
JF - Physical review letters
IS - 4
M1 - 046401
ER -