title: Control of molecular organization and energy level alignment by an electronically nanopatterned boron nitride template.
abstract: Suitable templates to steer the formation of nanostructure arrays on surfaces are indispensable in nanoscience. Recently, atomically thin sp(2)-bonded layers such as graphene or boron nitride (BN) grown on metal supports have attracted considerable interest due to their potential geometric corrugation guiding the positioning of atoms, metallic clusters or molecules. Here, we demonstrate three specific functions of a geometrically smooth, but electronically corrugated, sp(2)/metal interface, namely, BN/Cu(111), qualifying it as a unique nanoscale template. As functional adsorbates we employed free-base porphine (2H-P), a prototype tetrapyrrole compound, and tetracyanoquinodimethane (TCNQ), a well-known electron acceptor. (i) The electronic moirons of the BN/Cu(111) interface trap both 2H-P and TCNQ, steering self-organized growth of arrays with extended molecular assemblies. (ii) We report an effective decoupling of the trapped molecules from the underlying metal support by the BN, which allows for a direct visualization of frontier orbitals by scanning tunneling microscopy (STM). (iii) The lateral molecular positioning in the superstructured surface determines the energetic level alignment; i.e., the energy of the frontier orbitals, and the electronic gap are tunable.
authors: Physik Department E20, Technische Universität München , James Franck Strasse 1, D-85748 Garching, Germany.
authors: Sushobhan
authors: S
authors: Joshi
authors: Felix
authors: F
authors: Bischoff
authors: Ralph
authors: R
authors: Koitz
authors: David
authors: D
authors: Ecija
authors: Knud
authors: K
authors: Seufert
authors: Ari Paavo
authors: AP
authors: Seitsonen
authors: Jürg
authors: J
authors: Hutter
authors: Katharina
authors: K
authors: Diller
authors: José I
authors: JI
authors: Urgel
authors: Hermann
authors: H
authors: Sachdev
authors: Johannes V
authors: JV
authors: Barth
authors: Willi
authors: W
authors: Auwärter