Frequency doubler based on a single MoTe2/MoS2anti-ambipolar heterostructure

Abstract

The frequency doubler is a fundamental element in high frequency integrated circuits, which is usually implemented by a large number of devices in conventional configurations. In this article, we demonstrate a frequency doubler consisting of only one single heterostructure device by stacking two atomically thin MoTe2 and MoS2 flakes together. The resultant MoTe2/MoS2 heterostructure exhibits prominent anti-ambipolar characteristic after rapid thermal annealing treatment, which effectively modulates the p-doping level of the MoTe2, and thus, the transfer characteristic of the MoTe2/MoS2 heterojunction. The anti-ambipolar behavior gives the transfer curve of the MoTe2/MoS2 heterojunction an inverted "V"shape, based on which the source - drain current of the junction oscillates at a frequency that is twice that of the signal frequency inputted through the gate electrode. As a result, the frequency of the output voltage on the loading resistance doubles the input signal frequency. The developed frequency doubler functions well within 3 kHz, which may be improved by optimizing the device structure. This approach greatly reduces the total number of devices required to achieve the function of frequency doubling, and therefore, may achieve higher degree of integration.