On-surface synthesis of functional organic nanostructures

Amelia Dominguez Celorrio

Research output: Other contributionResearch

Abstract

The improvement of electronic device efficiency is currently based on the miniaturization of existing electronic devices. The manufacturing costs of reducing the size of semiconductor based circuits below 10 nm is unfeasible for companies. To overcome this limitation, other materials are currently being developed to fabricate equivalent electronic circuits with smaller dimensions. In this context, on-surface synthesis (OSS) is a bottom-up manufacturing technique based on the reaction of molecules to achieve a well-defined organic structure. The atomic precision of OSS allows to create functional organic molecules for molecular electronic devices. Scanning probe microscopy techniques are the most common microscopy techniques used to analyze on-surface synthesized structures. In this thesis, we present the synthesis by OSS and characterization by scanning tunneling microscopy (STM) and spectroscopy (STS) techniques of functional nanostructures. The synthesized manganese phthalocyanine (MnPc) includes in the phthalocyanine ring four diarylethylene moieties (DAE). The DAE moiety is an optically active group. This organo-metallic complex with optically active groups and the Mn in its structure could work as a magneto-optical transducer. We have successfully induced reversible switches with the STM tip between the assigned open and closed configurations of the DAE moiety. The other organic structures synthesized by OSS studied in this thesis are chiral graphene nanoribbons (ch-GNRs) on Ag(001). Combining STM and STS techniques we have studied the evolution of the electronic structure of ch-GNRs depending on their width and length. Furthermore, when the ch-GNRs are relocated on top of MgO monoloayers grown on the same Ag(001) substrate by means of atomic manipulation, a combination of charge transfer and electronic localization gives rise to a critical discretization of the extended edge states. This causes unprecedented long life times of the ribbon’s electronic states and spin splitting of the frontier orbitals ascribed to electron-electron correlations. Finally, we have evaluated the suitability of the ch-GNR/MgO monolayer/Ag(001) system as a molecular spin polarized transistor.
Original languageEnglish
Typethesis
PublisherUniversidad de Zaragoza
Number of pages156
Place of PublicationSpain
ISBN (Print)9788413405605
Publication statusPublished - Dec 2021
Externally publishedYes

Keywords

  • On-surface synthesis
  • Graphene nanoribbons
  • Magneto-optical transducers
  • Scanning tunneling microscopy (STM)

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