Highly sensitive MoS2 photodetector on polarized thin-film lithium niobate with extremely low dark current

Abstract

To obtain high performance optoelectronic devices, ferroelectric materials have received a lot of attention due to the various emerging effects on channel materials induced by the ferroelectric polarization. In this work, a special photodetector with the channel material of a triple-layer MoS2 on a polarized LiNbO3 substrate was fabricated. The device has a high responsivity of 113.1[Formula: see text]A/W and a high specific detectivity of up to [Formula: see text] Jones under red illumination, while maintaining the rise and fall time of 32 and 22[Formula: see text]ms, respectively. Meanwhile, the dark current of this device can be as low as [Formula: see text][Formula: see text]A with a bias of 5.0[Formula: see text]V because the channel material MoS2 is almost depleted under the internal electrical field induced by the polarized LiNbO3. This work promises a feasible way for the future development of integrated high-sensitivity photodetectors.