Optical properties of polysilanes and related materials

A review is given on our late experimental investigations on optical properties of polysilanes and related materials with various dimensions and networks. In particular, we argue the control of electronic structures by chemical modification of Si/Ge polymer structure and compositions. We show some successful examples to achieve wavelength-tunable luminescence bands in polysilanes/polygermanes, network copolymers, and polymorphic octasilacubanes.