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CPP: Chemische Physik und Polymerphysik

CPP 1: Thin Films and Surfaces I

CPP 1.6: Vortrag

Montag, 27. März 2006, 11:15–11:30, ZEU Lich

Regular Nano-dot Patterns by Dewetting of Thin Organic Films — •Stephan Rath, Mark Heilig, and Helmut Port — 3. Phys. Inst. Universität Stuttgart

The dewetting of thin organic films UHV-deposited on He-cooled substrate is analyzed by optical and AFM microscopies. By controlled annealing to room temperature such films can be transformed into patterns of isolated droplets. The description of the dewetting process takes advantage of the close similarity to pattern formation and dynamics in thin polymer films (polystyrene). Typical dewetting stages are discerned: spinodal hole formation, inhomogeneous extension of the hole, transformation into droplets via fingering and Rayleigh instabilities followed by droplet coarsening.

Films of a fulgide derivative, deposited on quartz glass substrates in the thickness range between 2 and 22 nm, will be considered as example. On smooth substrate surfaces, however, only irregular pattern of droplets are formed. In order to achieve regular patterns which are of interest for applications in molecular electronics and photonics, structured substrates are used as templates. In this way regular patterns of nano-dots with variable sizes and lateral distances have been produced.