O.Gürlü; "Through the seeing needle:Scanning Tunneling...", 27.04.2006

Faculty of Engineering and Natural Sciences
FENS SEMINARS

Through the seeing needle: “Scanning Tunneling Microscopy and Spectroscopy on
Metal/Semiconductor Surfaces”

Oğuzhan Gürlü
Max Planck Institute for Solid State Research, Nano-scale Science Department,
Stuttgart, Germany

Although young, Scanning Tunneling Microscopy (STM) is one of the most powerful techniques of surface science. The inherent atomic resolution offered by this technique makes it unequivocally the real tool of nano-science, along with several others that stemmed from STM (like AFM, SNOM, etc). Moreover, with the introduction of Scanning Tunneling Spectroscopy  (STS), it became possible to perform spectroscopic measurements on nano-structures with sub-nanometer resolution, which was lacked by the conventional tools of spectroscopy. Consequently, this technique constitutes an important part in the beginning of a new era with concepts like artificial atomic structures, quantum mirages, one dimensional magnetism, molecular electronics, etc.

Using STM and STS, we investigate the morphological and electronic properties of clean semiconductor and metal surfaces, metal nano-structures, ultra-thin insulating films and molecular systems grown on metal surfaces. In the first part of this talk STM and STS studies performed on clean Si(001) and Ge(001) surfaces will be focused on. The unique opportunity to observe a local metallic surface state with STS will be exemplified on Ge(001) surface. Next, the formation of Pt atomic chains on Ge(001) surfaces will be shown illustrating our metallic thin film growth studies on semiconductor surfaces. Following the discussion over semiconductor and metal-on-semiconductor systems, the STM and STS studies on the growth of ultra-thin insulating layers on metal surfaces will be addressed. The atomic modeling of mono and bi layers of KCl films on Cu surfaces will be presented along with the band gap measurement of these films. The talk will be concluded with the presentation of the application of STM to molecular systems and nano-photonics.

Biography:
Oguzhan Gurlu was born in 1976 in Eskisehir, Turkey.  After traveling many cities during his pre-university studies, he was admitted to the Bilkent University Physics Department at Ankara, where he obtained his BS degree in 1999. After his undergraduate study, he attained his MS degree in 2000 and his PhD degree in 2004 at the University of Twente, the Netherlands. Upon completion of his PhD study he received the Max Planck Fellowship for continuing his research at the Max Planck Institute, Stuttgart, Germany. From October 2004 till January 2006, he worked as a postdoctoral researcher at this institute and he continues to be a member of the Max Planck Society as a research scientist at the nano-scale science department. The research interests of Oguzhan Gurlu are focused on the morphological and electronic studies of the surfaces and interfaces of metals and semiconductors at the atomic scale. Additionally he works on the development of new surface science techniques with a focus on novel scanning probe methods for the study of molecular and magnetic nano structures.

April 27, 2006, 13:40, FENS 2019