Highly Efficient Polarization‐Controlled Electrical Conductance Modulation in a van der Waals Ferroelectric/Semiconductor Heterostructure

Abstract Utilizing the unique in‐plane/out‐of‐plane polarization coupling in ferroelectric van der Waals α‐In 2 Se 3 , ferroelectric‐polarization‐controlled electrical conductance modulation in two‐dimensional (2D) MoS 2 with a large dynamic range of over 5 orders of magnitude and excellent non‐volatility is demonstrated. This highly efficient control of the electrical conductance is facilitated by enhanced capacitive coupling through atomic‐layer‐deposition‐grown Al 2 O 3 as the dielectric medium. By varying the in‐plane poling bias to the ferroelectric α‐In 2 Se 3 , the electrical conductance of vertically stacked 2D MoS 2 can be tuned continuously. This approach enables simplified device design and provides great flexibility in device integrations, and it can be applied in principle to manipulate the electronic states in any 2D semiconductors for various applications such as transistors, tunneling devices, and reconfigurable electronics. The results also provide insight into the ferroelectric polarization screening by ambient chemical species, highlighting the need for surface passivation, and/or device encapsulations.