Analysis of the structure of -sexithiophene thin films grown on layered materials

Kodama, Hiraku*; Hiraga, Kenta*; Ono, Shinya*; Sekiguchi, Tetsuhiro  ; Baba, Yuji  ; Tanaka, Masatoshi*

Orientation of organic semiconductor has been important issue because of its strong anisotropy of the electronic property. We have investigated the orientation effect of -sexithiphene (6T) molecule deposited on WSe or GaSe substrate, which is layered semiconductor material. Thickness was controlled by regulating deposition rate and time. Orientation angle was analyzed by angle-resolved NEXAFS spectroscopy. The results show that molecular orientation angle depend not only on the substrate but also the thickness. Tilt angle is thought to be determined by the energy stability due to the commensurate at the interface as well as the molecule-substrate interaction.