The observation of reflection high energy electron diffraction (RHEED) oscillations has been proved to be a key to open the nano-world of materials, since it definitely verifies that the film growth proceeds in layer-by-layer mode with each layer thickness controllable by simply counting the number of oscillations. This enabled the fabrication of nano-engineered hetero-junctions and devices as commonly practiced for conventional semiconductors and metals. Here we report on the first observation of clear RHEED intensity oscillation in thin film fabrication of a φ-conjugated molecular solid. The observation has been achieved by coupling a novel deposition method using a continuous-wave infrared laser for evaporation and a high sensitive RHEED detector, in addition to the combinatorial optimization of film deposition parameters that facilitated our preceding first success in the layer-by-layer growth of oxide thin films. Some details of system design and experimental conditions are presented to discuss the key factors for atomically controlled film growth of molecular solids.
ASJC Scopus subject areas
- Physics and Astronomy(all)