Fourth Prize: "Thymine "integrated circuits" grown on silver terminated silicon (111) R3 x R3"

Author: Mr Cornelius Krull Freie Universitat Berlin (Germany)

STM nanowires

Image Description:

The STM image shows rows of thymine dimers forming geometric patterns. The defined angles closely resemble the structures found on an integrated circuit board. They stand in direct contrast to the organic shapes of the substrate. The color tones express the classical esthetics of STM images. The nulceobase thymine forms in the DNA helix complex structures based hydrogen bonding with its conjugated pair adenine. This bonding is one of the key parts in cellular life. But even thymine alone can form structures based on that capacity e.g. on Ag/Si(111) R3xR3. Here thymine was deposited in-situ to a 120 K cold sample, and then annealed to 300 K for 20 min. The molecules find each other through molecular recognition and homopair into strong dimers based on hydrogen bonding. The energy provided during annealing is sufficient for the dimers to self assemble into long rows along the directions of the substrate. The thickness of the rows is determined by the rigidness of the thymine dimer