Combined microscopic analyses of organic hetero-interface

Double-layered heterostructures of organic materials induced by epitaxial g rowth were investigated by microscopic analyses. Crystallographic orientati on and mutual registration of organic double-layers were examined by combin ed methods of high resolution imaging and energy-filtered imaging in transm ission electron microscopy, and also by atomic force microscopy. Three kind s of growth modes have been reported for the double-layers depending on the combination of molecules deposited: random growth, side growth and selecti ve on-top growth. In the present study, the most interesting, selective on- top growth, was studied by the combined method. It was concluded that such growth selectivity originated from the surface topography of the underlying organic layers, but not from lattice matching and/or chemical interaction between the two layers.