The interaction of metal-molecule-metal junctions with light is considered within a simple generic model. We show, for the first time, that light-induced current in unbiased junctions can take place when the bridging molecule is characterized by a strong charge-transfer transition. The same model shows current-induced light emission under potential bias that exceeds the molecular excitation energy. Results based on realistic estimates of molecule-lead coupling and molecule-radiation field interaction suggest that both effects should be observable.

• Received 7 March 2005

DOI:https://doi.org/10.1103/PhysRevLett.95.206802