Structural and optical characterization of epitaxially grown polysilane thin films

Structural and orientational studies of polydimethylsilane (PDMS). (Si(CH3)2)n, thin films evaporated on a KCl (001) substrate have been conducted by a newly developed energy-dispersive grazing-incidence X-ray diffraction system. The evaporated PDMS molecules grow epitaxially on the KCl (001), aligning their chain axes in the KCl 〈110〉 direction with a fluctuation of about 8.8 °. Therefore, the PDMS molecules prefer to align their chain axes along rows of the same ions. Moreover, the polarized UV absorption spectra of the epitaxially grown PDMS thin films show characteristic optical properties depending on their molecular orientation.