Electrostatic Gating-Dependent Multiple Band Alignments in Ferroelectric α-InSe/α-Te van der Waals Heterostructures.

The two-dimensional ferroelectric van der Waals (vdW) heterojunction has been recognized as one of the most promising combinations for emerging ferroelectric memory materials due to its noncovalent bonding and flexible stacking of various materials. In this work, the first-principles calculations were performed to study the stable geometry and electronic structure of α-InSe/α-Te, incorporating the vdW correction via the DFT-D2 method. The reversal of the polarization direction in α-InSe can induce a transition in the heterostructure from metallic to semiconductor, accompanied by a shift from type-III to type-I band alignment.

Harnessing a silicon carbide nanowire photoelectric synaptic device for novel visual adaptation spiking neural networks.

Visual adaptation is essential for optimizing the image quality and sensitivity of artificial vision systems in real-world lighting conditions. However, additional modules, leading to time delays and potentially increasing power consumption, are needed for traditional artificial vision systems to implement visual adaptation. Here, an ITO/PMMA/SiC-NWs/ITO photoelectric synaptic device is developed for compact artificial vision systems with the visual adaption function.

Janus monolayer PXC (X = As/Sb) for photocatalytic water splitting with a negative Poisson's ratio.

Two-dimensional (2D) Janus materials have attracted considerable attention in photocatalysis owing to their robust redox capability and efficient segregation. In this study, we propose a novel Janus monolayer structure, denoted as PXC (X = As/Sb), exhibiting favorable stability in terms of dynamics, thermal properties, and mechanical characteristics. The PXC monolayers demonstrate a relatively smaller Young's modulus (132.

First-principles prediction of ferroelectric Janus SiXY (X/Y = S/Se/Te, X ≠ Y) monolayers with negative Poisson's ratios.

Nowadays, two-dimensional (2D) materials with Janus structures evoke much attention due to their unique mechanical and electronic properties. In this work, Janus Pma2-SiXY (X/Y = S/Se/Te, X ≠ Y) ferroelectric monolayers are firstly proposed and systematically investigated by first-principles calculations. These monolayers exhibit remarkable mechanical properties, including small Young's modulus values, negative Poisson's ratios (NPRs) and large critical strains, reflecting their exceptional flexibility and stretchability.

Electrostatic gating dependent multiple band alignments in ferroelectric VS/GaO van der Waals heterostructures.

Two-dimensional (2D) van der Waals (vdW) heterostructures with spontaneous intrinsic ferroelectrics play an essential role in ferroelectric memories. Also, the reversal of polarized directions induces band alignment transitions among different types to provide a new path for multifunctional devices. In this work, the structural and electronic properties of 2D VS/GaO vdW heterostructures under different polarizations were investigated using first-principles calculations with the vdW correction of the DFT-D2 method.

Robust ferroelectricity in low-dimensional -SiX (X = S/Se): a first-principles study.

Low-dimensional ferroelectric materials hold great promise for application in nonvolatile memory devices. In this work, ferroelectricity in two-dimensional monolayers and one-dimensional nanowires based on -SiX (X = S and Se) materials with spontaneous polarization and ferroelectric switching energy barriers has been predicted using the first-principles method. The results show that the intrinsic ferroelectric values due to spontaneous polarization of 2D-SiS, 2D-SiSe, 1D-SiS and 1D-SiSe are 3.