Coulomb Blockade Tuned by NO₂ Molecules in Nanostructured Silicon

Electrochemical etching of heavily doped Si can be used as a simple self- assembly technique for the fabrication of Si nanocrystal arrays. The obtained nanostructures exhibit Coulomb- blockade behavior at room temperature, and are very sensitive to the presence of molecules with high electron affinities, such as NO2 (see figure). Tunable gas sensors that work at room temperature can thus be obtained.