Pentacene Multilayers on Ag(111) Surface


Creative Commons License

METE E., Demiroglu I., DANIŞMAN M. F., Ellialtioglu S.

JOURNAL OF PHYSICAL CHEMISTRY C, cilt.114, sa.6, ss.2724-2729, 2010 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 114 Sayı: 6
  • Basım Tarihi: 2010
  • Doi Numarası: 10.1021/jp910703n
  • Dergi Adı: JOURNAL OF PHYSICAL CHEMISTRY C
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.2724-2729
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

The structural profiles and electronic properties of pentacene (C22H14) multilayers on Ag(111) surface has been studied within the density functional theory framework. We have performed first-principle total energy calculations based on the projector-augmented wave method to investigate the initial growth patterns of pentacene (Pn) on Ag(111) surface. In its bulk phase, pentacene crystallizes with a triclinic symmetry while a thin film phase having an orthorhombic unit cell is energetically less favorable by 0.12 eV/cell. Pentacene prefers to stay planar on Ag(111) surface and aligns perfectly along silver rows without any molecular deformation at a height of 3.9 angstrom. At one monolayer (ML) coverage, the separation between the molecular layer and the surface plane extends to 4.1 angstrom due to intermolecular interactions weakening surface-pentacene attraction. While the first ML remains flat, the molecules on a second full pentacene layer deposited on the surface rearrange so that they become skewed with respect to each other. This adsorption mode is energetically more preferable than the one for which the molecules form a flat pentacene layer by an energy difference similar to that obtained for bulk and thin film phases. Moreover, as new layers are added, pentacenes assemble to maintain this tilting for 3 and 4 ML, similar to its bulk phase, while the contact layer always remains planar. Therefore, our calculations indicate bulklike initial stages for the growth pattern.