In‐Plane Polarization Induced Depletion, Photovoltaic and Memory Effects in Ferroelectric Junction Field‐Effect Transistor

Abstract Ferroelectric transistors hold great promise for multifunctional electronic devices, but challenges such as polarization loss, gate leakage currents, and breakdown voltage limitations persist, necessitating further optimization for low‐power applications. Hence, a novel device structure using ferroelectric semiconductors CuInP 2 S 6 (CIPS) is proposed to construct a MoS 2 junction field‐effect transistor (JFET), leveraging the non‐volatile polarization for zero‐power depletion modulation and the junction structure to eliminate leakage currents. As a photodetector, the remnant polarization field in CIPS depletes channel carriers in MoS 2 , suppressing dark current of MoS 2 transistor from 2 × 10 −9 A to 7 × 10 −14 A, and accelerating photocarrier recombination, reducing response time by up to 89% (@520 nm) as compared to pristine MoS 2 . The device demonstrates high‐stability photodetection with a responsivity ( R ) of 20 A W −1 and specific detectivity ( D * ) of 1.2 × 10 11 Jones (@405 nm) over 10 4 s at room temperature. Depending on the non‐centrosymmetric nature of CIPS, the heterojunction device exhibits a photovoltaic effect, achieving an open‐circuit voltage ( V oc ) of 0.82 V and a short‐circuit current density ( J SC ) of 0.24 mA cm −2 . As a ferroelectric JFET, the device showcases non‐volatile memory properties with pJ‐level energy consumption, stable endurance over 2000 write‐erase cycles, and retention exceeding 10 4 s with no obvious decay. This work provides new insights for the development of future multifunctional electronic devices.