Optical properties of polysilanes and related materials

Summary form only given. Polymers containing silicon into the backbone have recently attracted much interest from the viewpoint of unique optical properties. The dimension of the Si-polymer backbone can be controlled by organic chemical substitution of the sidegroups, which ranges from zero- to two-dimensional structures. In particular, the one-dimensional linear Si-polymer is referred to as polysilanes. As far as the electronic structures are concerned, these Si-polymers may be viewed as ultimate quantum boxes, quantum wires, and quantum wells, respectively. In this paper, we review our late experimental investigations on the optical properties arising from the difference in the dimensional electronic structures in Si-polymers. We will focus on the linear and nonlinear optical properties associated with the one-dimensional excitonic structures and control of optical gap by changing the two-dimensional polymer structures.