Epitaxially Grown Strained Pentacene Thin Film on Graphene Membrane

Kwanpyo Kim, Elton J.G. Santos, Tae Hoon Lee, Yoshio Nishi, Zhenan Bao

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

Organic-graphene system has emerged as a new platform for various applications such as flexible organic photovoltaics and organic light emitting diodes. Due to its important implication in charge transport, the study and reliable control of molecular packing structures at the graphene-molecule interface are of great importance for successful incorporation of graphene in related organic devices. Here, an ideal membrane of suspended graphene as a molecular assembly template is utilized to investigate thin-film epitaxial behaviors. Using transmission electron microscopy, two distinct molecular packing structures of pentacene on graphene are found. One observed packing structure is similar to the well-known bulk-phase, which adapts a face-on molecular orientation on graphene substrate. On the other hand, a rare polymorph of pentacene crystal, which shows significant strain along the c-axis, is identified. In particular, the strained film exhibits a specific molecular orientation and a strong azimuthal correlation with underlying graphene. Through ab initio electronic structure calculations, including van der Waals interactions, the unusual polymorph is attributed to the strong graphene-pentacene interaction. The observed strained organic film growth on graphene demonstrates the possibility to tune molecular packing via graphene-molecule interactions. Graphene can induce the growth of a rarely-observed pentacene polymorph through graphene-molecule interaction.

Original languageEnglish
Pages (from-to)2037-2043
Number of pages7
JournalSmall
Volume11
Issue number17
DOIs
Publication statusPublished - 2015 May 6

All Science Journal Classification (ASJC) codes

  • Biotechnology
  • Biomaterials
  • Chemistry(all)
  • Materials Science(all)

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    Kim, K., Santos, E. J. G., Lee, T. H., Nishi, Y., & Bao, Z. (2015). Epitaxially Grown Strained Pentacene Thin Film on Graphene Membrane. Small, 11(17), 2037-2043. https://doi.org/10.1002/smll.201403006