An analytic approach to the conductance and I-V characteristics of polymeric chains

Electron transport is studied in a molecular device made of two semi-infinite leads connected by a molecule. Both the molecule and the leads are described within the tight-binding model. Using a transfer matrix method, the transmission is calculated, taking into account a finite potential difference between the leads. In several interesting cases, such as some oligomeric chains of arbitrary length, the use of the transfer matrix method allows us to obtain explicit results for the transmission for finite bias voltage. From our transmission results, we obtain the current-voltage characteristics for short molecular chains and discuss a dependence of the current on the coupling between the molecules and the leads.