# Giant Tunneling Electroresistance and Anisotropic Photoresponse in Sliding Ferroelectric Homojunctions Based on Bilayer Janus MoSSe

## TL;DR

This paper explores how sliding layers in a special type of material can control electrical resistance and light response, offering new possibilities for low-power electronics and sensors.

## Contribution

The study introduces a novel homophase lateral architecture using bilayer Janus MoSSe to achieve giant tunneling electroresistance and anisotropic photoresponse.

## Key findings

- Sliding from AB to BA configuration reduces current from nA to pA range, achieving 5.3 × 10⁴% tunneling electroresistance.
- The p–i–n photodetector shows anisotropic response with AB stacking outperforming BA by 1.5–1.8 times in photocurrent density.
- Local density of states analysis reveals polarization-driven tunneling modulation and high-transmission channels.

## Abstract

Interlayer-sliding ferroelectricity in van der Waals bilayers enables ultralow-power switching, but practical devices are often limited by contact/interface scattering and weak coupling between polarization and transport. We propose homophase lateral architectures based on bilayer Janus MoSSe: a 1T/2H/1T ferroelectric tunnel homojunction and an H-phase lateral p–i–n photodetector (artificially doped electrode). Metallic 1T electrodes largely eliminate contact barriers and maximize polarization-driven tunneling modulation. Using non-equilibrium Green’s function–density functional theory (Perdew–Burke–Ernzerhof approximation, without explicit spin–orbit coupling), we find that AB to BA sliding reduces the current from the nA range to the pA range, with the minimum current of|IOFF|min = 2.83 pA, yielding giant tunneling electroresistance up to 5.3 × 104%. Projected local density of states reveals a non-rigid long-range potential redistribution that reshapes the tunneling barrier and opens high-transmission channels. In the p–i–n photodetector, the response is strongly anisotropic and stacking-dependent: AB reaches photocurrent density Jph ≈ 7.2 µA·mm−2 at 2.6 eV for in-plane light versus ≈ 2.9 µA·mm−2 at 3.5 eV for out-of-plane, and exceeds BA by 1.5–1.8 times due to density of states advantages and Mo-d orbital selection rules. Bilayer Janus MoSSe therefore provides a reconfigurable platform for high-contrast memory and polarization-sensitive photodetection.