Photoinduced removal of the Franck-Condon blockade in single-electron inelastic charge transmission

A new mechanism of charge transmission through a metal - molecule-metal junction is suggested that is based on optical driving of electronic transitions in the neutral and singly charged molecular state. The effects of strong electron vibrational coupling, intramolecular vibrational energy redistribution, and molecular de-excitation caused by electron-hole pair formation in the leads are taken into account. It is shown that current suppression due to the Franck-Condon blockade can be overcome by opening new transmission channels via photoexcitation.