Nano Lettershttp://dx.doi.org/10.1021/nl201773d (2011)

Credit: © 2011 ACS

Applying reliable electrical contacts to self-assembled molecular monolayers poses a persistent challenge in molecular electronics. Evaporated metal top electrodes can cause short circuits at monolayer defects, and solution-processed conducting polymer electrodes may show temperature-dependent electrical characteristics that disguise the physics of molecular charge transport. Carlos Cesar Bof Bufon and colleagues have now developed a process that allows them to contact molecular monolayers using predefined metal and inorganic semiconductor layers. Their approach is based on epitaxially grown strained membranes that curl up as an underlying sacrificial layer is removed. The membranes can be designed such that they contact a molecular monolayer on a predefined bottom electrode after the release. Alternatively, one side of a multilayered membrane can be functionalized to form a rolled-up cylindrical semiconductor–monolayer–semiconductor junction. The approach enables device cross-sections below 1 μm2. The authors have studied contacts from gold and III–V semiconductors so far, and they suggest that their method could be expanded to other strained layers.