Viable single-molecule diodes

(Nanowerk News) Benefiting from the Molecular Foundry’s expertise in molecular modeling, researchers have designed a new technique to create single-molecule diodes that perform 50 times better than all prior designs.
Individual molecules represent the gold standard for electronics miniaturization, which leads to improved performance, greater utility and lower costs.
A collaborative team of researchers, including Foundry Director Jeff Neaton and users from Columbia University led by Latha Venkataraman, have designed a new technique to create single-molecule diodes that perform 50 times better than all prior designs (Nature Nanotechnology, "Single-molecule diodes with high rectification ratios through environmental control").
With electronic devices becoming smaller every day, the field of molecular electronics has become ever more critical in solving the problem of further miniaturization, and single molecules represent the limit of miniaturization.
A diode is a fundamental building block of integrated circuits that acts as an electricity valve. A diode must be asymmetric so that electricity flowing in one direction experiences a different environment than electricity flowing in the other.
Single-molecule diodes have been demonstrated but have suffered from very low current flow and low current flow asymmetry. Instead of using an asymmetric molecule, the team improved performance by 50 times by creating asymmetry in the molecule’s environment: an ionic solution and gold metal electrodes of different sizes.
Source: Department of Energy