Toward Ferroelectric Control of Monolayer MoS₂

Abstract

The chemical vapor deposition (CVD) of molybdenum disulfide (MoS2) single-layer films onto periodically poled lithium niobate is possible while maintaining the substrate polarization pattern. The MoS2 growth exhibits a preference for the ferroelectric domains polarized "up" with respect to the surface so that the MoS2 film may be templated by the substrate ferroelectric polarization pattern without the need for further lithography. MoS2 monolayers preserve the surface polarization of the "up" domains, while slightly quenching the surface polarization on the "down" domains as revealed by piezoresponse force microscopy. Electrical transport measurements suggest changes in the dominant carrier for CVD MoS2 under application of an external voltage, depending on the domain orientation of the ferroelectric substrate. Such sensitivity to ferroelectric substrate polarization opens the possibility for ferroelectric nonvolatile gating of transition metal dichalcogenides in scalable devices fabricated free of exfoliation and transfer.

Nonvolatile MoS2 field effect transistors directly gated by single crystalline epitaxial ferroelectric

“…Figure 4c directly compares the transfer curves of the MoS2 ferroelectric transistors fabricated on smooth and rough surfaces, showing that transistors fabricated on rough surfaces have hysteresis loops in the clockwise direction (i.e. anti-hysteresis), similar to those results reported before, not only of MoS2 but also of graphene [6][7][8][9][13][14][15] . Since the only difference between those two systems having different loop directions are the surface topography of PZT gate oxide layers, we postulate that a dominant reason for anti-hysteresis is interface states induced by defects on a rough surface.…”

Combined electrical transport and capacitance spectroscopy of a MoS2-LiNbO3 field effect transistor

“…All experimental data is found to be in excellent agreement with an analytical model based on a 2D electron system over the entire range of V GS . Most strikingly we find that for our device the values of µ FE obtained solely from the I SD − V GS overestimates those obtained taking into account the measure C−V GS by more than a factor of ×4.The sample studied consists of 128 • Y-rotated, d = 0.5 mm thick substrate of black lithium niobate (LiNbO 3−x ), on top of which a layer of MoS 2 has been deposited by chemical vapour deposition 18,19 . We use such samples for investigations of the interaction of surface acoustic waves with MoS 2 , as described in ref.…”

Understanding the intrinsic water wettability of graphite

“…312 Moreover, Santos and Kaxiras manipulated the dielectric constant of MoS 2 by an external electric field indicating viability for use in uniquely tuned electronic devices. Interestingly, they also propose exfoliation of monolayers using the induced interlayer charge imbalance.…”