Molecular diodes and negative differential resistances based on polyoxometalates

By measuring the tunnel conductivity of polyoxometalates (POM) and their organic derivatives in experiments with a scanning tunnel microscope (STM), effects have been found which are promising for use in nanoelectronics. Large-scale multiple negative differential resistances (with record peak-to-valley ratios up to 102) have been observed under conditions which do not require low temperatures and high vacuum. The diode properties of organo-polyoxometalate complexes with coefficients of rectification up to 35–40 are revealed. A mechanism of biresonance tunnel electron transport in strong electric fields, which explains the effects, has been developed. A strategy for selecting nanomaterials which can improve the functional properties of molecular electronic elements based on the optimization of the composition and architecture of polyoxometalate complexes has been proposed.