Hot wall epitaxial growth of highly ordered organic epilayers

Abstract

Hot wall epitaxy works close to thermodynamic equilibrium and is therefore most applicable for materials with Van der Waals binding character. The hot wall epitaxy system can be described as semiclosed growth reactor, consisting of a vertically mounted quartz cylinder, which is heated by three separately controllable ovens, and is closed on top by the substrate. The first oven heats the source material and controls the growth rate. The second heats the hot wall between source and substrate, which guaranties the closed character of the reactor and helps to avoid loss of valuable material. The third oven controls the substrate temperature and allows to influence the growth process on the substrate surface. We achieved crystalline perfection for C 60 layers on mica substrates and fabricated Ba-doped n-type layers with mobilities of 6000 cm 2/V s at room temperature.