Using Lipophilic Membrane for Enhanced-Performance Aqueous Gated Carbon Nanotube Field Effect Transistors

Electrolyte gated carbon nanotube field effect transistors have great potential in bio-sensing applications. However, when the application requires aqueous-medium electrolytes the performance of field effect based sensors is compromised because of the restriction in the applied voltages. In this work, use of lipophilic poly(vinyl chloride) based membranes containing tetradodecylammonium tetrakis(4-chlorophenyl)boronate, for encapsulating the channel of the transistor is demonstrated for the first time. This process is performed in ambient atmosphere after fabrication of field effect transistors, hence making it highly lucrative for low cost sensors. A significant improvement in the transistor parameters like increase in on-off ratio, low hysteresis and reduction in the leakage current are observed, with a negative impact in the on-current. A comparative study on the impact of membrane composition on the transistor performance is also presented. Toward the end, significant improvement in the performance of a pMOS inverter using membrane on the load and driver transistors is demonstrated.