2006 年 33 巻 4 号 p. 236-
Dendritic growth of pentacene (Pn) thin film crystals on a H-Si(111) surface was observed in situ by low-energy electron microscopy. We found that each dendrite branch is always composed of three domains with different orientations of 2D unit cells (Fig. 1(a)), and the center domain whose b axes of the 2D unit cell is parallel to the growth direction of the dendrite branch grows faster than outer two domains. This result indicates the direction of the b axis of the Pn 2D unit cell is a preferential growth direction. In addition, since the b axes of the outer two domains are rotated ±60 deg in relation to that of the center domain (Fig. 1(a)), the outer directions of the branch are the preferential growth directions of the outer domains. Hence, when a child branch appears, the outer domain of the mother branch becomes a center domain of the child branch.