Quantum dynamics of charge carriers in donor-bridge-acceptor molecular segments with applications to molecular electronics.

摘要

The theory of electron transfer (ET) is important toward understanding the physics and process technology of electronic devices at the atomic and molecular scale. Computer simulation of ID model Hamiltonians has proven to be an effective method to study the ET processes in molecular electronic devices. In this thesis, we present our findings on electron transfer rate (ETR) in model molecular quantum wire (MQW) and donor-bridge-acceptor (DBA) molecular chain systems as our ID electron systems.; In this thesis, we show that our trigonometric imaging method (TIM) is an excellent approach to calculating ETR both in MQW and DBA chain systems. First, we report the results on ETR using exact formulas for MQW and DBA chain systems without any nonlinear interactions and find that these results are the same as those obtained by TIM. We introduce a graphical approach to get time derivatives as necessary data for TIM to study the nonlinear effects, electron-phonon (e-p) and electron-electron (e-e) interactions, on ETR in a MQW. We show that time derivatives obtained by the graphical approach are the same as those obtained exactly in the case of e-p interactions. We conclusively report using both the exact and TIM results that e-p interactions enhance ETR in a MQW. Our research on nonlinear interactions also shows that temperature enhances ETR in a model MQW. Using TIM, we report that e-e interactions have virtually no effect on ETR in a MQW, where the data for TIM are obtained by the graphical approach.