Allgemeines Physikalisches Kolloquium im Wintersemester 2009/2010
Ort:    48149 Münster, Wilhelm-Klemm-Str. 10, IG I, HS 2,
Zeit:    Donnerstag, 21.01.2010 16:00 Uhr c.t.
Kolloquiums-Kaffee ab 15:45 Uhr vor dem Hörsaal

Realizing surface nanostructures with high structural regularity, tuneable properties and diverse applications
Dr. Yong Lei, Institut für Materialphysik und CeNTech, WWU Münster

Surface nano-patterns and nanostructures are of great importance in fabricating a wide range of nano-devices. Using the emerging UTAM (ultra-thin alumina masks) surface nano-patterning technique that was proposed by our group, large-scale ordered arrays of surface nano-structures (nanodots and nanoholes) were fabricated on flat substrates. The structural parameters (size, spacing, and shape) of the UTAM-fabricated surface nanostructures can be adjusted by controlling the pore size of the UTAMs. The advantageous of the UTAM surface nano-patterning, such as the achievement of tuneable structural parameters and properties, large pattern area, high throughput and low equipment costs, make the technique suitable to fabricate ordered surface nanostructures with a broad range of applications ranging from optical, sensing, and electronic devices.
Recently, we advanced the UTAM nano-patterning technique by a new fabrication route to prepare UTAMs with regularly arrayed pores in the quantum-sized range and consequently to synthesize ordered arrays of quantum-dots. Using a modulated anodization process combined with a well-controlled pore-opening process, the pore-size of UTAMs can be well-controlled in the range of 5 to 27 nm. Ordered arrays of surface nanodots within the similar size range were fabricated. This is the first time in realizing large-scale regularly arrayed surface nanostructures with the quantum-sized diameters using the UTAM surface nano-patterning technique.
Another very important and challenging topic in the field of surface nano-structuring is the realization of three-dimensional (3-D) surface nano-patterning, which is one of the main topics that are investigating now in our group. Well-defined one-dimensional (1-D) surface nanostructures realized by the 3-D surface nano-patterning provide an excellent system to analyze and control the physical properties of large ensembles of surface nanostructures. For the well-defined 1-D surface nanostructure arrays, it is possible to analyze both the properties of the individual unit and the coupling interaction between the adjacent units. By integrating these data, the properties of the whole ensembles could be obtained. This ‘bottom-up’ property investigation will pave the way to a complete property tuning based on the structural design of surface nanostructures.