Efficient and Long-Lasting Current Rectification by Laminated Yet Separated, Oppositely Charged Monolayers

Abstract

When two oppositely charged self-assembled monolayers of thiolates on gold are laminated-but with their (+/-) end groups kept apart by just a few angstroms-and then electrically poled, they form a sandwich structure featuring a large, permanent internal dipole. This supramolecular assembly acts as an efficient current rectifier, achieving rectification ratios exceeding 10(3), switching times on the order of tens of mu s, and undiminished performance over at least 10(4) seconds of continuous operation under bias.