Basic properties of electrolyte-oxide-semiconductor structures with applications in biochemical sensing

We present the basic properties and potential applications of a kind of electrolyte-oxide-semiconductor (EOS) structure, which is composed of a Si layer, a SiO2 layer, and an electrolyte solution layer, from bottom to top. It is demonstrated that the EOS structures exhibit a stable one-way electrical conductivity like a diode, and there is a threshold voltage in the ON-switching process. Moreover, it is found that the thicknesses of SiO2 layers and the concentrations of electrolyte solutions affect the current density obviously. A conductive-filament model is proposed to analyze the conductivity mechanism of EOS structures. The EOS structures can be used for many biochemical applications. We have realized copper-ion detection and pH sensing by utilizing their basic characteristics. ? 2014 IEEE.EI