Type‐II AsP/As van der Waals Heterostructures: Tunable Anisotropic Electronic Structures and Optical Properties

Abstract

The weak vdW interlayer interactions between the constituent layers do not introduce remarkable changes at the atomic scale, but can extend the electronic, mechanical, optical and other properties of 2D materials. Therefore, by integrating together the virtue of its building monolayers, the vdW heterostructures have the opportunity to provide a versatile platform for exploring new phenomena and designing novel materials for high-performance electronic devices, [4-8] optoelectronic device, [9] chemical sensors, [10] water-splitting photocatalysts, [11-13] and thermoelectric generators. [14] Arsenene (As), a new cousin of phosphorene in group VA, has been predicted in 2015 to be a semiconductor with a wide indirect bandgap (puckered: 0.83 eV; buckled: 1.64 eV), desirable stability and high carrier mobility using density functional theory (DFT), suggesting its potential applications for transistors with high on/off ratios, optoelectronic devices working under blue or UV light. [15-17] In experiment, multilayered arsenene nanoribbons with 14 nm thickness and 2.3 eV bandgap have been successfully synthesized on an InAs substrate by the plasma-assisted process in 2016. [18] Very recently, a freestanding buckled arsenene has been fabricated experimentally with a lattice constant of 3.6 Å on Ag(111). [19] Recently, arsenic-phosphorus (AsP), another new promising 2D layered material, is an alloy of phosphorus and arsenic atoms in the forms of As x P 1−x with excellent electronic and optical properties via tuning the chemical compositions during material synthesis. [20] Long and co-workers have reported the black AsP-based long-wavelength infrared photodetector working at room temperature and it can response to 8.2 µm light experimentally. [21] Later, gated-photoconductors based on b-AsP alloys have been performed as a function of thickness over the composition range of 0-91% As. [22] The specific detectivity can be optimized by adjusting the thickness of the b-P/b-AsP layer to maximize absorption and minimize dark current. In addition, the black phosphorus based infrared photodetectors with fast response of 16 µ s and broadband photodetection up to 2 µm have also been demonstrated in experiments. [23] Subsequently, growing attention has been focused on As and AsP materials in group VA. Particularly, the enthusiasm of researchers has been kindled to study the As-or AsP-based vdW heterojunctions. [24-37] A blue-AsP/CdSe heterostructure van der Waals (vdW) heterostructures, formed by stacking layered materials, have great potential for next-generation nanoelectronics and optoelectronics with unique flexibility and high performance. Using density functional theory, it is demonstrated that all AA-and AB-AsP/As heterostructures are semiconductors with intrinsic type-II band alignments, facilitating the separation of photogenerated electron-hole pairs. The anisotropic electronic structures of the puckered AsP/As vdW heterostructures can be effectively modulated by applying tensile strains. The bandgaps exhibit nonmonotonic varia...

Type‐II van der Waals Heterostructures Based on AsP and Transition Metal Dichalcogenides: Great Promise for Applications in Solar Cell

“…So, type-II AsP/MoS 2 AA, AB stacking, AsP/WS 2 AA, AB stacking, and WSe 2 /AsP AA' stacking vdW heterostructures render potential applications in the field of photovoltaic materials. [29] 3.4. Optical Properties and Promising Applications in Potential Solar Cells…”

“…[27] There have been some theoretical investigations on AsP-based vdW heterostructures. [12,28,29] Blue-AsP/CdSe heterostructure with a conversion efficiency of about 13% has been studied, and it may become a novel solar cell material. [12] The BP/beta-AsP vdW heterostructure has gone deep into type-II band alignment.…”

“…These properties facilitate its practical application in nanoelectronic devices and photovoltaics. [29] Transition metal chalcogenides (TMDs) with similar lattice constants of β-AsP have also become research hotspots in recent years represented by MX 2 (M ¼ Mo, W and X ¼ S, Se). MX 2 monolayers are direct-bandgap semiconductors that exist stably at room temperature.…”

“…These properties facilitate its practical application in nanoelectronic devices and photovoltaics. [ 29 ]…”

Mo2CF2/WS2: Two-Dimensional Van Der Waals Heterostructure for Overall Water Splitting Photocatalyst from Five-Step Screening

“…As a semiconductor material with an adjustable band gap, they can promote the absorption of visible light and improve the utilization efficiency of visible light. , The conduction band minimum (CBM) and valence band maximum (VBM) of MoS 2 and WS 2 are higher than those of most photosensitive semiconductors, which will make more conduction band (CB) electrons migrate and valence band (VB) holes migrate when they are used as auxiliary control materials, thus promoting the excitation of electron–hole (e-h) pairs. Recently, several kinds of heterostructures of MoS 2 and WS 2 with other 2D layers have been verified by experiments and theories and show potential applications in optoelectronics, catalysis, energy storage, and nanosensors …”