Low-noise platform for in situ structural and electrical characterization by sub-Ångstrøm low-voltage transmission electron microscopy (SALVE IV)

• Applicants: Professorin Dr. Ute Kaiser; Professor Carl Emil Krill III, Ph.D.; Professor Dr. Ferdinand Scholz
• Subject Area: Synthesis and Properties of Functional Materials
• Term: from 2009 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 89228805

This project is intended to develop a low-noise platform for investigating beam-sensitive samples at sub-Ångstrøm resolution using low-voltage transmission electron microscopy, enabling simultaneous imaging and in situ variation of the electrical bias applied to the specimen. By means of the focused ion-beam (FIB) technique, submicrometer-sized slits will be cut in silicon nitride membranes and then covered by single-layer sheets of graphene, yielding a weakly scattering, perfectly crystalline sample support whose signal can be removed from the TEM image by Fourier filtering. Metallic microcontacts will be added to the platform by lithography, and the remaining gap to the sample will be bridged by nanowires deposited by FIB, thereby making it possible to pass electrical current through a specimen during observation in the TEM. This capability will be exploited to study (i) the influence of lattice defects and/or adsorbates on the electrical conductivity of graphene and (ii) the structure and electrical properties of ultrathin layers of semiconductors like GaN and AlN.

• DFG Programme: Research Grants
• Major Instrumentation: TEM single-tilt heating holder
• Instrumentation Group: 5190 Sonstige elektronenoptische Geräte (außer 404 und 510-518)