scholarly journals Strain-Induced Tunable Band Offsets in Blue Phosphorus and WSe2 van der Waals Heterostructure

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 470
Author(s):  
Lingxia Zhang ◽  
Le Huang ◽  
Tao Yin ◽  
Yibin Yang

The electronic structure and band offsets of blue phosphorus/WSe2 van der Waals (vdW) heterostructure are investigated via performing first-principles calculations. Blue phosphorus/WSe2 vdW heterostructure exhibits modulation of bandgaps by the applied vertical compressive strain, and a large compressive strain of more than 23% leads to a semiconductor-to-metal transition. Blue phosphorus/WSe2 vdW heterostructure is demonstrated to have a type-II band alignment, which promotes the spontaneous spatial separation of photo-excited electrons and holes. Furthermore, electrons concentrating in BlueP and holes in WSe2 can be enhanced by applied compressive strain, resulting in an increase of carrier concentration. Therefore, these properties make blue phosphorus/WSe2 vdW heterostructure a good candidate for future applications in photodetection.

2021 ◽  
Vol 23 (6) ◽  
pp. 3963-3973
Author(s):  
Jianxun Song ◽  
Hua Zheng ◽  
Minxia Liu ◽  
Geng Zhang ◽  
Dongxiong Ling ◽  
...  

The structural, electronic and optical properties of a new vdW heterostructure, C2N/g-ZnO, with an intrinsic type-II band alignment and a direct bandgap of 0.89 eV at the Γ point are extensively studied by DFT calculations.


2018 ◽  
Vol 20 (47) ◽  
pp. 29931-29938 ◽  
Author(s):  
Wenzhen Dou ◽  
Anping Huang ◽  
Hongliang Shi ◽  
Xinjiang Zhang ◽  
Xiaohu Zheng ◽  
...  

The separation of photoexcited electron–hole pairs in the BP/P4O10 vdW heterostructure.


RSC Advances ◽  
2020 ◽  
Vol 10 (53) ◽  
pp. 32027-32033
Author(s):  
Thi-Nga Do ◽  
M. Idrees ◽  
Bin Amin ◽  
Nguyen N. Hieu ◽  
Huynh V. Phuc ◽  
...  

We investigate the structural, electronic, optical and photocatalytic properties of boron phosphide and SiC monolayers and their corresponding van der Waals heterostructure by density functional theory.


Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 991
Author(s):  
Zhengyang Zhu ◽  
Kai Ren ◽  
Huabing Shu ◽  
Zhen Cui ◽  
Zhaoming Huang ◽  
...  

In this paper, the optical and electronic properties of WSSe/BSe heterostructure are investigated by first-principles calculations. The most stable stacking pattern of the WSSe/BSe compounds is formed by van der Waals interaction with a thermal stability proved by ab initio molecular dynamics simulation. The WSSe/BSe heterostructure exhibits a type-I band alignment with direct bandgap of 2.151 eV, which can improve the effective recombination of photoexcited holes and electrons. Furthermore, the band alignment of the WSSe/BSe heterostructure can straddle the water redox potential at pH 0–8, and it has a wide absorption range for visible light. In particular, the solar-to-hydrogen efficiency of the WSSe/BSe heterostructure is obtained at as high as 44.9% at pH 4 and 5. All these investigations show that the WSSe/BSe heterostructure has potential application in photocatalysts to decompose water.


2020 ◽  
Vol 22 (37) ◽  
pp. 21436-21444
Author(s):  
Wei Sheng ◽  
Ying Xu ◽  
Mingwei Liu ◽  
Guozheng Nie ◽  
Junnian Wang ◽  
...  

The type-II band alignment promotes InSe/SiH as a high efficiency photocatalyst for water splitting in visible light.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Junyi Liu ◽  
Zi Li ◽  
Xu Zhang ◽  
Gang Lu

AbstractRecent experiments observed significant energy transfer in type-II van der Waals (vdW) heterostructures, such as WS2/MoSe2, which is surprising due to their staggered band alignment and weak spectral overlap. In this work, we carry out first-principles calculations to shed light on energy and charge transfer in WS2/MoSe2 heterostructure. Incorporating excitonic effect in nonadiabatic electronic dynamics, our first-principles calculations uncover a two-step process in competing energy and charge transfer, unravel their relative efficiencies and explore the means to control their competition. While both Dexter and Förster mechanisms can be responsible for energy transfer, they are shown to operate at different conditions. The excitonic effect is revealed to drive ultrafast energy and charge transfer in type-II WS2/MoSe2 heterostructure. Our work provides a comprehensive picture of exciton dynamics in vdW heterostructures and paves the way for rational design of novel vdW heterostructures for optoelectronic and photovoltaic applications.


Author(s):  
Jia-Le Chen ◽  
Jing-Xue Du ◽  
Jing Yang ◽  
Lijie Shi

Abstract Vertical van der Waals heterostructures(vdWH) composed of two monolayer materials can provide new opportunities for layered electronic devices. Here we present a detailed theoretical investigation about the electronic properties of BP/SnS vdWH by applying in-plane uniaxial and biaxial strains. Our first principles calculations suggest that the direct bandgap of BP/SnS vdWH can be maintained within a large range of uniaxial and biaxial strains. We also find that the bandgap, band alignment and contact type of BP/SnS vdWH can be tuned by uniaxial and biaxial strains. In addition, the Poisson’s ratio exhibits an intense anisotropy with respect to the uniaxial strain along zigzag and armchair directions. The easily tunable electronic properties and highly anisotropic character of BP/SnS vdWH make it to be a promising material in the field of photovoltaic cells, photodetectors, and other functional nano devices.


Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1565
Author(s):  
Yuliang Mao ◽  
Zheng Guo ◽  
Jianmei Yuan ◽  
Tao Sun

Based on first-principles calculations, we propose van der Waals (vdW) heterojunctions composed of one-dimensional carbon nanotubes (CNTs) and two-dimensional GeSe. Our calculations show that (n,0)CNT/GeSe (n = 5–11) heterojunctions are stable through weak vdW interactions. Among these heterojunctions, (n,0)CNT/GeSe (n = 5–7) exhibit metallic properties, while (n,0)CNT/GeSe (n = 8–11) have a small bandgap, lower than 0.8 eV. The absorption coefficient of (n,0)CNT/GeSe (n = 8–11) in the ultraviolet and infrared regions is around 105 cm−1. Specifically, we found that (11,0)CNT/GeSe exhibits type-II band alignment and has a high photoelectric conversion efficiency of 17.29%, which suggests prospective applications in photoelectronics.


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