N. Uyeda, Yukio Murata
May 1, 1982
Citations
0
Influential Citations
4
Citations
Journal
Journal of Crystal Growth
Abstract
Abstract The mechanism of epitaxial growth of organic semiconductors on an alkali halide (KCl) has been studied by electron microscopy. Bromanil (C6Br4O2) and iodanil (C6I4O2), which are well known to be strong electron acceptors, were studied. Electron diffract ion revealed that the epitaxial film consists of crystallites having two orientations which are essentially identical but normal to each other. For bromanil, the b-axis coincided with [110] or [1 1 10] of KCl and the a-axis was normal to the substrate surface. Epitaxially grown iodanil crystals had different structure from the bulk form. Growth of a polymorph could be induced by the strong interaction between deposit and substrate. It was deduced from mutual orientation that oriented adsorption in such a way that four halogen atoms in a molecule locate closely to potassium ions first governs the epitaxial nucleation and that the appearance of better lattice fit between two extended lattices may strongly affect subsequent epitaxial growth.