Thickness-modulated lateral MoS2 diodes with sub-terahertz cutoff frequency

Abstract

Thickness-modulated lateral MoS₂ diodes with an extracted benchmark cutoff frequency (f_c) of up to 126 GHz are implemented and fully characterised. Fabricated diodes demonstrate an on–off current ratio of more than 600 and a short circuit current responsivity at zero-bias of 7 A/W. The excellent performance achieved in our device is attributed to reduced contact resistance from using In/Au contacts and low junction capacitance due to the lateral device structure. In addition, the use of multilayer MoS₂ crystals enabled relatively high current flow. Small- and large-signal models are extracted from DC and RF characterisation of the fabricated diode prototype. Extracted compact models are compared to the measured DC and S-parameters of the diode, demonstrating excellent matching between models and measurements. The presented diode is suitable for switching circuits and high frequency applications.