Reversible switching of single tin phthalocyanine molecules on the InAs(111)A surface

• Published in: Journal of physics. Condensed matter Vol. 24; no. 39; p. 394004
• Main Authors: Nacci, C, Kanisawa, K, Fölsch, S
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 03.10.2012; Institute of Physics
• Subjects: Condensed matter; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Physics; Planes; Scanning tunneling microscopy; Semiconductors; Surface chemistry; Surface conductivity and carrier phenomena; Switching; Tin; Tunnel junctions; Scanning tunneling microscopy; Reversible processes; Semiconductor materials; Adsorption; Molecular structure; Molecular assembly; Metallophthalocyanine; Tin complexes; Tunnel junction; Indium arsenides; Switching
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/24/39/394004

Individual tin phthalocyanine (SnPc) molecules adsorbed on the InAs(111)A surface were studied by low-temperature scanning tunnelling microscopy (STM) at 5 K. Consistently with the nonplanar molecular structure, SnPc adopts two in-plane adsorption geometries with the centre Sn atom either above (SnPcup) or below (SnPcdown) the molecular plane. Depending on the current and bias applied to the tunnel junction, the molecule can be reversibly switched between the two conformations, implying a controlled transfer of the Sn atom through the molecular plane. The SnPcdown conformer is characterized by an enhanced surface bonding as compared to the SnPcup conformer. SnPcup molecules can be repositioned by the STM tip by means of lateral manipulation, whereas this is not feasible for SnPcdown molecules. The reversible switching process thus enables one to either laterally move the molecule or anchor it to the semiconductor surface.