Molecular junctions: from tunneling to function

Thanks to the development of appropriate experimental techniques, molecular devices and their electrical transport properties have recently been the focus of a major research effort. This brief review describes how individual molecules can be contacted with metallic electrodes to form molecular junctions and addresses their basic formation mechanisms. An extension to molecular junctions networks is also discussed. Functionality could be demonstrated in such systems, and examples where conductance modulation using light or chemical stimuli was achieved will be presented.