Hybrid silicon/molecular FETs: A study of the interaction of redox-active molecules with silicon MOSFETs

Redox-active molecular monolayers were incorporated in silicon MOSFETs to obtain hybrid silicon/molecular FETs. Cyclic voltammetry and FET characterization techniques were used to study the properties of these hybrid devices. The redox-active molecules have tunable charge states, which are quantized at room temperature and can be accessed at relatively low voltages. The discrete molecular states were manifested in the drain current and threshold voltage characteristics of the device, confirming the presence of distinct energy levels within the molecules at room temperature. This study demonstrates the modulation of Si-MOSFETs' drain currents via redox-active molecular monolayers. The single-electron, functionality provided by the redox-active molecules is ultimately scalable to molecular dimensions, and this approach can be extended to nanoscale field-effect devices including those based on carbon nanotubes. The molecular states coupled with CMOS devices can be utilized for low-voltage, multiple-state memory and logic applications and can extend the impact of silicon-based technologies.