Solid polyelectrolyte-gated surface conductive diamond field effect transistors

Solid polyelectrolytes have been used in transistor devices to achieve gating with high capacitance. We use a solid polyethylene oxide/LiClO4 electrolyte to replace aqueous electrolytes as a gate for surface-conductive diamond field-effect transistors (FET). The resulting transistor shows characteristics comparable to those of aqueous electrolyte-gated diamond FETs. We investigate the polyelectrolyte/diamond interface with impedance spectroscopy and cyclic voltammetry, showing the electrochemical stability of the interface and capacitive gating up to 100 Hz. Hall effect measurements on the polyelectrolyte-gated devices are compared to those with liquid gates. The solid and transparent polyelectrolyte gates promise further applications for surface-conductive diamond FETs.