title: Simple model of a coherent molecular photocell.
abstract: Electron transport in molecular electronic devices is often dominated by a coherent mechanism in which the wave function extends from the left contact over the molecule to the right contact. If the device is exposed to light, photon absorption in the molecule might occur, turning the device into a molecular photocell. The photon absorption promotes an electron to higher energy levels and thus modifies the electron transmission probability through the device. A model for such a molecular photocell is presented that minimizes the complexity of the problem while providing a non-trivial description of the device mechanism. In particular, the role of the molecule in the photocell is investigated. It is described within the Hückel method and the source-sink potential approach [F. Goyer, M. Ernzerhof, and M. Zhuang, J. Chem. Phys. 126, 144104 (2007)] is used to eliminate the contacts in favor of complex-valued potentials. Furthermore, the photons are explicitly incorporated into the model through a second-quantized field. This facilitates the description of the photon absorption process with a stationary state calculation, where eigenvalues and eigenvectors are determined. The model developed is applied to various generic molecular photocells.
authors.affiliation: Département de Chimie, Université de Montréal, C.P. 6128 Succursale A, Montréal, Québec H3C 3J7, Canada.
authors.forename: Matthias
authors.initials: M
authors.lastname: Ernzerhof
authors.affiliation: Département de Chimie, Université de Montréal, C.P. 6128 Succursale A, Montréal, Québec H3C 3J7, Canada.
authors.forename: Marc-André
authors.initials: MA
authors.lastname: Bélanger
authors.affiliation: Institut Néel, CNRS, F-38042 Grenoble, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Mayou
authors.affiliation: Institut Néel, CNRS, F-38042 Grenoble, France.
authors.forename: Tahereh
authors.initials: T
authors.lastname: Nemati Aram