Design and manipulation of high-performance photovoltaic systems based on two-dimensional novel KAgSe/KAgX(X=S,Te) van der Waals heterojunctions

Keying Han; Qiang Wang; Yan Liang; Defeng Guo; Bin Wang

Home/Archive/arXiv

arXiv · 2306.15921

Design and manipulation of high-performance photovoltaic systems based on two-dimensional novel KAgSe/KAgX(X=S,Te) van der Waals heterojunctions

Keying Han·Qiang Wang·Yan Liang·Defeng Guo·Bin Wang

View original source ↗Read source document ↗Export metadata ↓

Abstract

The realization of high-performance two-dimensional (2D) solar photovoltaic systems are both fundamentally intriguing and practically appealing to meet the fast-growing energy requirements. Since the limited application of single 2D crystals in photovoltaic, here we propose a family of 2D KAgSe/KAgX(X=S,Te) van der Waals heterostructures (vdWHs), which are constructed by combining two different KAgX layers through interlayer vdW interaction. After a systematic study and further regulatory research of these vdWHs based on the first-principles, numerous fascinating characteristics and physical mechanisms are obtained. Firstly, favorable potential applications of these vdWHs in photovoltaics are confirmed in virtue of their desirable optoelectronic properties, such as the robust stabilitis, moderate direct band gaps, type-II band alignments together with superior carrier mobilities, visible optical absorptions, power conversion efficiencys (PCEs) and photocurrents in their based photovoltaic devices. More importantly, when under varying vertical electric field Ez, a phase transition of band alignment from type-II to type-I of these vdWHs can be induced by the opposite band shifts between layers, which may enrich their applications in light-emitting diodes and lasers. Meanwhile, the PCE can be expanded up to 23%, and an obvious red-shift peak of the photocurrent in the visible light range are also obtained at different Ez. These fascinating tunable properties of KAgSe/KAgX vdWHs under varying Ez not only promote the improvement of their photoelectric performances, but the underlying mechanisms can also be applied to next experimental design and practical application of other 2D photovoltaic systems. Especially for the red-shift peak of the photocurrent, which is rarely found but highly desirable in practical visible photoelectric conversion.

Explore related subjects

physics.comp-ph cond-mat.mtrl-sci

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Keying Han, Qiang Wang, Yan Liang, Defeng Guo, Bin Wang. 2023-06-28. Design and manipulation of high-performance photovoltaic systems based on two-dimensional novel KAgSe/KAgX(X=S,Te) van der Waals heterojunctions. https://arxiv.org/abs/2306.15921

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Bi-Hamiltonian in Semiflexible Polymers built upon Overdamping Process

Quantifying the interaction between a system of interest and its ambient conditions, the memory effect links the states of two distinct Hamiltonians: one for the target system and one for the environment. In this paper, we propose the diffusion process derived from the Smoluchowski equation that can derive the evolution process described by the memory effect integration in a non Markovian regime. The Smoluchowski picture, within the framework of stochastic thermodynamics, justifies a diffusion process incorporated into the equations of motion, and the result of the derivation enables a coarse-grained molecular dynamics simulation with the modified equation of motion to reproduce attenuation from collisions between single walled carbon nanotubes (SWCNTs) under far from equilibrium conditions. The results of the numerical experiments on the collision confirm that heat diffusion compensates for the correlated momentum arising from the memory effect between the two Hamiltonians in both equilibrium and far from equilibrium states.

physics.comp-ph↗

arXiv2026

Learning continuous reaction paths for transition-state prediction

Transition states are defined by reaction pathways, yet most machine-learning methods predict them as isolated geometries. We introduce MARC-TS, a two-stage framework that learns a continuous, endpoint-conditioned path, queries it at any resolution and uses local path context to refine a transition-state candidate. We construct T1x-IRC-8K, a dataset of 8,209 reactions and 1,088,725 path-resolved geometries. On held-out reactions, the path model reduced complete-path error by 48.4% relative to endpoint interpolation, and the localizer achieved a mean aligned structural error of 0.127 Å. Quantum-chemical optimization and vibrational analysis yielded 405 frequency-confirmed first-order saddle-point candidates from 410 predictions. In a 100-reaction nudged elastic band comparison, learned-path initialization reached a joint geometry-and-force target for 66% of reactions, compared with 12% for geometric interpolation after 100 optimizer steps. By treating the path as a reusable representation rather than an auxiliary output, MARC-TS connects transition-state prediction, mechanistic interpretation and quantum-chemical refinement.

physics.comp-ph↗

arXiv2026

A subcell-refined entropy-residual-driven limiting strategy for high-order discontinuous Galerkin methods

Fine-grained, subcell-level dissipation control is essential for achieving robust high-order discontinuous Galerkin (DG) simulations of nonlinear hyperbolic systems in under-resolved regimes while preserving accuracy. This paper proposes a subcell-refined entropy-residual-driven limiting strategy for DG on Legendre-Gauss-Lobatto nodes. The limiter introduces only nearest-neighbor pairwise dissipation within each element, with closed-form coefficients that supply the minimal dissipation required to restore the element entropy inequality. The strategy is a diagonal, locally stable approximation of classical entropy-stable methods, and a generalized subcell framework reveals split-form DG and residual-distribution-based entropy correction schemes as particular choices of the limiting coefficients. For the Euler equations, a physically consistent jump operator separately models thermal and shear entropy production while preserving velocity and pressure equilibrium; a subcell refinement of the Zhang-Shu positivity limiter ensures pointwise positivity. Extensive numerical tests confirm that the scheme maintains optimal high-order accuracy, strictly enforces entropy dissipation, and significantly reduces the difficulty of a posteriori positivity-preserving procedures.

physics.comp-ph↗