Fabrication of liquid-gated molybdenum disulfide field-effect transistor

Abstract

Two-dimensional molybdenum disulfide is gradually emerging as the novel semiconductor material(channel) to connect two electrodes (source and drain) of field-effect transistor. For effective detecting the biological molecules, a newly liquid-gated molybdenum disulfide field-effect transistor was fabricated in this paper. Molybdenum disulfide film was transferred to cover the silicon nitride substrate on which the drain and source electrodes were deposited. The through hole was created on the back of the silicon nitride substrate. Then the field-effect transistor was immersed in electrolyte, and the NaCl solution was as the gate. The electrical characterization of the device was investigated in air and in buffer respectively. The results indicated that in buffer the contact between the drain and source electrodes through molybdenum disulfide film was ohmic and the molybdenum disulfide film resistance was smaller than that in air, which was due to the solution ions doped into molybdenum disulfide film. Additionally, the contact resistance was decreased with the increasing of the back-gate voltage, which showed that the liquid-gated molybdenum disulfide field-effect transistor's contact resistance had a strong dependence on the back-gate voltage.