Identifying the Ground-State NP Sheet through a Global Structure Search in Two-Dimensional Space and Its Promising High-Efficiency Photovoltaic Properties

Abstract

Recently fabricated two-dimensional (2D) black phosphorene (BP) is considered to be a promising optoelectronic sheet, but its applications are hindered by the poor stability in air. Thus, it is desirable to investigate other BP-like 2D materials, which may have improved stability, while preserving the exceptional electronic properties of BP. Herein, using an efficient structure search method, we predicted a novel 2D BP-like material, namely, a honeycomb NP sheet (α-NP). Remarkably, its few-layer α-NP sheets possess not only a tunable direct bandgap under in-plane strain but also high mobility (×10 4 cm 2 V −1 s −1 ) and absorption coefficients (×10 5 cm −1 ). These advantageous characteristics endow the α-NP sheets as a very potential 2D material for efficient photovoltaic cell applications, as demonstrate by an estimated photovoltaic efficiency of ∼14%, when its thickness is at ∼1 μm. When combined with 2D MoTe 2 , it can provide a type-II heterojunction solar cell with a conversion efficiency up to ∼16%. We also proposed a feasible strategy for mechanical cleavage to prepare the α-NP sheets from its bulk NP compound. Once prepared, the α-NP sheets may offer superior photovoltaic properties and facilitate the development of solar cells and optoelectronic devices.C onverting solar energy into electrical power using semiconductor materials is very promising to satisfy the ever-increasing demand for renewable energy. 1,2 Many bulk inorganic semiconductor materials, such as Si, GaAs, CdTe, 3−6 and conjugated polymers, 7−9 have been utilized, with varying degrees, as solar energy convertors. Compared with these traditional bulk semiconductor materials, two-dimensional (2D) semiconductors offer a promising alternative for the feasible construction of ultrathin solar cells with high conversion efficiency and flexibility. 10 Such 2D semiconductor materials typically have large contact areas for optical absorption, which could be straightforwardly engi-

Giant Shift Photovoltaic Current in Group V‐V Binary Nanosheets

“…The bond lengths of the two binary compounds are shown in Figure 1b,e and they vary from 1.73 to 2.40 Å, while the bond angles vary from 97.55°t o 123.47°. The structural cell parameters used in this study are summarized in Table1, and are in excellent agreement with previous studies [37,38]. On average the cell parameters differ only by ≈0.21% and ≈0.43% for 𝛼-AsP and 𝛼-NP, respectively.…”

“…The two binary V-V compounds have been established to show high stabilities under ambient conditions, [35][36][37] and compared with other 2D materials they have been reported to show better optical responses in low frequencies. [38,39] With reduced symmetries and low dimensions, they can induce more nonzero components of SC susceptibilities and enhanced SC response which may result in an improvement in the conversion efficiency of incident light. [40] From the analysis of the contributions of different transitions, the critical role played by electronic energy bandgap in SC is affirmed.…”

“…[54] 𝜎 = slab thickness layer thickness 𝜎 slab (2) 1, and are in excellent agreement with previous studies. [37,38] On average the cell parameters differ only by ≈0.21% and ≈0.43% for 𝛼-AsP and 𝛼-NP, respectively. On the other hand, only the bond lengths of 𝛼-AsP were found in reported results, and on average differed only by ≈1.8% from the reported ones.…”

A novel 2D porous C3N2 framework as a promising anode material with ultra-high specific capacity for lithium-ion batteries

“…A wide-ranging structure search was conducted by employing a particle swarm optimization algorithm (PSO) as implemented in the CALYPSO code, 36,37 whose ability to efficiently nd ground or metastable structures in both bulk materials and 2D materials has been well recognized. [38][39][40][41][42][43][44][45] All of our simulations, including structural search and property calculations, were performed using density functional theory (DFT) as implemented in the Vienna Ab Initio Simulation package (VASP), 46 VASPKIT 47 and qvasp 48 as pre-and post-processing tools. The electron-ion interaction was described by the projected augmented wave (PAW) 49 method, and the exchange-correlation term was treated by the Perdew-Burke-Ernzerhof (PBE) 50 functional within the generalized gradient approximation (GGA).…”

DFT Investigations on the Boron–Phosphorus Assembled Nanowires

“…They also have potential applications in energy and electronic devices [5][6][7][8][9]. In addition, researchers have also discovered a series of phosphorus-based binary compounds, such as PN, AsP, SbP and PB [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. Since these binary compounds are also anisotropic, they have similar physical properties to those of α-P, such as high mobility and adjustable bandgap.…”