  Heterostructures based on two dimensional (2D) materials offer the
possibility to achieve synergistic functionalities which otherwise remain
secluded by their individual counterparts. Herein ferroelectric polarization
switching in alpha-In2Se3 has been utilized to engineer multilevel non-volatile
conduction states in partially overlapping alpha-In2Se3-MoS2 based
ferroelectric semiconducting field effect device. In particular, we demonstrate
how the intercoupled ferroelectric nature of alpha-In2Se3 allows to
non-volatilely switch between n-i and n-i-n type junction configurations based
on a novel edge state actuation mechanism, paving the way for sub-nanometric
scale non-volatile device miniaturization. Furthermore the induced asymmetric
polarization enables enhanced photogenerated carriers separation resulting in
extremely high photoresponse of 1275 AW-1 in the visible range and strong
non-volatile modulation of the bright A- and B- excitonic emission channels in
the overlaying MoS2 monolayer. Our results show significant potential to
harness the switchable polarization in partially overlapping alpha-In2Se3-MoS2
based FeFETs to engineer multimodal non-volatile nanoscale electronic and
optoelectronic devices.
