Optical absorption of a dimerized interrupted strand model

The frequency-dependent susceptibility has been calculated in a one-electron tight-binding approximation for a half-filled dimerized linear chain of finite extent. It is shown that at finite temperatures the interruption of a semiconducting strand could lead to significant absorption in the gap. This absorption is associated with intraband transitions that would normally be absent for an infinite strand and consequently could provide evidence for the presence of interrupted strands. © 1977.