Diode characteristic of electrolyte-oxide-semiconductor structure for potential chemical and biological applications

This paper reports an abnormal diode characteristic of electrolyte-oxide-semiconductor (EOS) structure. The EOS structure is made up of an n-type silicon layer, a low-pressure-chemical-vapor-deposition SiO₂ layer and an electrolyte-solution layer, from bottom to top. It shows a stable one-way electrical conductivity when external voltages are applied between the electrolyte-solution and silicon layers. Nanopillar forests are employed in the structure to improve the forward-current value. The EOS structures with different cross-sectional areas and different electrolyte-solutions e.g. in concentrations and pH values are tested, illustrating this kind of half-nanofluidic diodes has a great potential for chemical and biological applications.