Growth process of pentacene crystals obtained by physical vapor transport technique

Abstract

The growth process of pentacene crystals obtained by the physical vapor transport technique is discussed on the basis of the results of optical microscopy and X-ray topography. At the initial stage of physical vapor growth, many pentacene whisker crystals were grown. After that, the morphology of the whiskers developed to dendrites. Then, the whisker crystals themselves became the main branches of the dendritic crystals formed at the initial stage, and many side branches were created from the lateral surfaces of the whisker crystals. Some of the dendritic crystals continued to develop to form plateletlike crystals with a dendritic configuration. Regarding the plateletlike crystals with a parallelogram configuration, traces of the dendrites are thought to sometimes be left inside these plateletlike crystals on the basis of the results of optical microscopy and X-ray topography. Plateletlike crystals with a parallelogram configuration are considered to sometimes grow via the formation of dendritic crystals.