Electronic states of highly ordered DNTT and picene molecular layer

Hasegawa, Yuri  ; Yamada, Yoichi*; Sasaki, Masahiro*

Molecular arrangements and electronic states of well-ordered (DNTT) and picene thin film on single crystal were measured by means of scanning tunneling microscope (STM) and angle-resolved photoemission spectroscopy, respectively. DNTT and picene form single crystalline-like molecular arrangement on inert Au(111) substrate. Splitting of HOMO energy due to overlapping with adjacent molecules was suggested by ultraviolet photoemission spectroscopy (UPS) and density functional theory (DFT) calculation. On the other hand, one-dimensional ordering of those molecule was observed on anisotropic Ag(110) substrate. However, the HOMO band dispersion was found to be 200 meV at maximum, showing that the overlapping of HOMO was smaller in such arrangement comparing with that in their single crystal.