Atomistic insight into the significantly enhanced photovoltaic cells of monolayer GaTe2via two-dimensional van der Waals heterostructures engineering

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Francis Opoku ◽  
Penny P. Govender
Keyword(s):  
Solar Cells ◽  
Charge Transfer ◽  
Density Functional ◽  
Van Der Waals ◽  
Photovoltaic Cells ◽  
Density Functional Theory Method ◽  
Binding Energies ◽  
Band Alignment ◽  
Two Dimensional ◽  
Photovoltaic Solar Cells

AbstractDesigning new van der Waals (vdW) heterostructures from various two-dimensional transition metal dichalcogenides (TMDs) materials shows outstanding properties, such as an ultrafast charge transfer process and strong interlayer interactions by combining the advantageous properties of the different TMD materials. In this study, using the density functional theory method, we systemically investigate the optical property, band alignment, electronic structures, interface charge transfer, mechanical properties and stability of MTe2/GaTe2 (M = Mo and W) vdW heterostructures as promising photovoltaic solar cells materials. In this work, gallium telluride and MTe2 were used as acceptors and donors in high-quality photovoltaic cells. The calculated binding energies suggest that they were energetically favourable and relatively easy to fabricate under suitable conditions. Moreover, the heterostructures possess exceptional characteristics of enhanced visible light absorption edge (∼104 cm−1), type-II band alignment and strong charge separation. The suitable band alignment leads to maximum power conversion efficiency (PCE) of 22.43 and 22.91%, respectively, which was quite promising for photovoltaic solar cells. The high PCE could be due to the internal built-in electric field at the MTe2/GaTe2 interface, which induces efficient separation of charge carriers. This work offers theoretical support for the design and prediction of next-generation low-cost, highly efficient and promising materials for solar device applications.

scholarly journals Electronic and photocatalytic properties of two-dimensional boron phosphide/SiC van der Waals heterostructure with direct type-II band alignment: a first principles study

RSC Advances ◽  
2020 ◽  
Vol 10 (53) ◽  
pp. 32027-32033
Author(s):  
Thi-Nga Do ◽  
M. Idrees ◽  
Bin Amin ◽  
Nguyen N. Hieu ◽  
Huynh V. Phuc ◽  
...  
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Van Der Waals ◽  
Band Alignment ◽  
Photocatalytic Properties ◽  
Type Ii ◽  
Two Dimensional ◽  
Functional Theory ◽  
Boron Phosphide ◽  
Van Der Waals Heterostructure

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.

scholarly journals PN/PAs-WSe2 van der Waals heterostructures for solar cell and photodetector

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Xinyi Zheng ◽  
Yadong Wei ◽  
Kaijuan Pang ◽  
Ngeywo Kaner Tolbert ◽  
Dalin Kong ◽  
...  
Keyword(s):  
Refractive Index ◽  
Solar Cells ◽  
Negative Refractive Index ◽  
Wide Spectrum ◽  
Van Der Waals ◽  
Band Alignment ◽  
Ultraviolet Region ◽  
Type I ◽  
Type Ii ◽  
Van Der Waals Heterostructures

Abstract By first-principles calculations, we investigate the geometric stability, electronic and optical properties of the type-II PN-WSe2 and type-I PAs-WSe2 van der Waals heterostructures(vdWH). They are p-type semiconductors with indirect band gaps of 1.09 eV and 1.08 eV based on PBE functional respectively. By applying the external gate field, the PAs-WSe2 heterostructure would transform to the type-II band alignment from the type-I. With the increasing of magnitude of the electric field, two heterostructures turn into the n-type semiconductors and eventually into metal. Especially, PN/PAs-WSe2 vdWH are both high refractive index materials at low frequencies and show negative refractive index at high frequencies. Because of the steady absorption in ultraviolet region, the PAs-WSe2 heterostructure is a highly sensitive UV detector material with wide spectrum. The type-II PN-WSe2 heterostructure possesses giant and broadband absorption in the near-infrared and visible regions, and its solar power conversion efficiency of 13.8% is higher than the reported GaTe–InSe (9.1%), MoS2/p-Si (5.23%) and organic solar cells (11.7%). It does project PN-WSe2 heterostructure a potential for application in excitons-based solar cells.

scholarly journals Cross-plane transport in a single-molecule two-dimensional van der Waals heterojunction

2020 ◽  
Vol 6 (22) ◽  
pp. eaba6714 ◽  
Author(s):  
Shiqiang Zhao ◽  
Qingqing Wu ◽  
Jiuchan Pi ◽  
Junyang Liu ◽  
Jueting Zheng ◽  
...  
Keyword(s):  
Charge Transport ◽  
Single Molecule ◽  
Density Functional ◽  
Electronic Materials ◽  
2D Materials ◽  
Molecular Layer ◽  
Van Der Waals ◽  
Density Functional Theory Calculations ◽  
Two Dimensional ◽  
Guest Molecules

Two-dimensional van der Waals heterojunctions (2D-vdWHs) stacked from atomically thick 2D materials are predicted to be a diverse class of electronic materials with unique electronic properties. These properties can be further tuned by sandwiching monolayers of planar organic molecules between 2D materials to form molecular 2D-vdWHs (M-2D-vdWHs), in which electricity flows in a cross-plane way from one 2D layer to the other via a single molecular layer. Using a newly developed cross-plane break junction technique, combined with density functional theory calculations, we show that M-2D-vdWHs can be created and that cross-plane charge transport can be tuned by incorporating guest molecules. The M-2D-vdWHs exhibit distinct cross-plane charge transport signatures, which differ from those of molecules undergoing in-plane charge transport.

Band alignment and charge transfer predictions of ZnO/ZnX (X = S, Se or Te) interfaces applied to solar cells: a PBE+U theoretical study

2018 ◽  
Vol 20 (7) ◽  
pp. 4953-4961 ◽  
Author(s):  
Efracio Mamani Flores ◽  
Rogério Almeida Gouvea ◽  
Maurício Jeomar Piotrowski ◽  
Mário Lucio Moreira
Keyword(s):  
Solar Cells ◽  
Charge Transfer ◽  
First Principles ◽  
Theoretical Study ◽  
Band Alignment ◽  
First Principles Calculations

We performed first-principles calculations within PBE and PBE+U approximations to study ZnO and ZnX bulk systems and ZnO/ZnX interfaces (X = S, Se or Te), to the better comprehension of charge transference through the interface.

Highly-efficient heterojunction solar cells based on two-dimensional tellurene and transition metal dichalcogenides

2019 ◽  
Vol 7 (13) ◽  
pp. 7430-7436 ◽  
Author(s):  
Kai Wu ◽  
Huanhuan Ma ◽  
Yunzhi Gao ◽  
Wei Hu ◽  
Jinlong Yang
Keyword(s):  
Solar Cells ◽  
Transition Metal ◽  
Charge Separation ◽  
Transition Metal Dichalcogenides ◽  
Band Alignment ◽  
Type Ii ◽  
Two Dimensional ◽  
Heterojunction Solar Cells ◽  
Highly Efficient ◽  
Metal Dichalcogenides

Tellurene and TMDs show desirable type II band alignment for constructing highly-efficient heterojunction solar cells with strong charge separation and enhanced sunlight absorption.

scholarly journals Observation of site-controlled localized charged excitons in CrI3/WSe2 heterostructures

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Arunabh Mukherjee ◽  
Kamran Shayan ◽  
Lizhong Li ◽  
Jie Shan ◽  
Kin Fai Mak ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Large Scale ◽  
Information Science ◽  
Van Der Waals ◽  
Spatial Location ◽  
Band Alignment ◽  
Tungsten Diselenide ◽  
Electrostatic Doping ◽  
Localized Excitons ◽  
Quantum Emitters

Abstract Isolated spins are the focus of intense scientific exploration due to their potential role as qubits for quantum information science. Optical access to single spins, demonstrated in III-V semiconducting quantum dots, has fueled research aimed at realizing quantum networks. More recently, quantum emitters in atomically thin materials such as tungsten diselenide have been demonstrated to host optically addressable single spins by means of electrostatic doping the localized excitons. Electrostatic doping is not the only route to charging localized quantum emitters and another path forward is through band structure engineering using van der Waals heterojunctions. Critical to this second approach is to interface tungsten diselenide with other van der Waals materials with relative band-alignments conducive to the phenomenon of charge transfer. In this work we show that the Type-II band-alignment between tungsten diselenide and chromium triiodide can be exploited to excite localized charged excitons in tungsten diselenide. Leveraging spin-dependent charge transfer in the device, we demonstrate spin selectivity in the preparation of the spin-valley state of localized single holes. Combined with the use of strain-inducing nanopillars to coordinate the spatial location of tungsten diselenide quantum emitters, we uncover the possibility of realizing large-scale deterministic arrays of optically addressable spin-valley holes in a solid state platform.

Binding Energies of Organic Charge-Transfer Complexes Calculated by First-Principles Methods

1998 ◽  
Vol 63 (8) ◽  
pp. 1223-1244 ◽  
Author(s):  
Cordula Rauwolf ◽  
Achim Mehlhorn ◽  
Jürgen Fabian
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Ground State ◽  
Density Functional ◽  
Binding Energies ◽  
Basis Set ◽  
Dispersion Energy ◽  
Functional Theory ◽  
Basis Set Superposition Error ◽  
Donor And Acceptor

Weak interactions between organic donor and acceptor molecules resulting in cofacially-stacked aggregates ("CT complexes") were studied by second-order many-body perturbation theory (MP2) and by gradient-corrected hybrid Hartree-Fock/density functional theory (B3LYP exchange-correlation functional). The complexes consist of tetrathiafulvalene (TTF) and related compounds and tetracyanoethylene (TCNE). Density functional theory (DFT) and MP2 molecular equilibrium geometries of the component structures are calculated by means of 6-31G*, 6-31G*(0.25), 6-31++G**, 6-31++G(3df,2p) and 6-311G** basis sets. Reliable molecular geometries are obtained for the donor and acceptor compounds considered. The geometries of the compounds were kept frozen in optimizing aggregate structures with respect to the intermolecular distance. The basis set superposition error (BSSE) was considered (counterpoise correction). According to the DFT and MP2 calculations laterally-displaced stacks are more stable than vertical stacks. The charge transfer from the donor to the acceptor is small in the ground state of the isolated complexes. The cp-corrected binding energies of TTF/TCNE amount to -1.7 and -6.3 kcal/mol at the DFT(B3LYP) and MP2(frozen) level of theory, respectively (6-31G* basis set). Larger binding energies were obtained by Hobza's 6-31G*(0.25) basis set. The larger MP2 binding energies suggest that the dispersion energy is underestimated or not considered by the B3LYP functional. The energy increases when S in TTF/TCNE is replaced by O or NH but decreases with substitution by Se. The charge-transferred complexes in the triplet state are favored in the vertical arrangement. Self-consistent-reaction-field (SCRF) calculations predicted a gain in binding energy with solvation for the ground-state complex. The ground-state charge transfer between the components is increased up to 0.8 e in polar solvents.

Two-Dimensional Polyfluorenes Bearing Thienylenevinylene π-Bridge-Acceptor Side Chains for Photovoltaic Solar Cells

2013 ◽  
Vol 117 (47) ◽  
pp. 24700-24709 ◽  
Author(s):  
Enwei Zhu ◽  
Jiefeng Hai ◽  
Zixuan Wang ◽  
Bin Ni ◽  
Yaohua Jiang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Side Chains ◽  
Two Dimensional ◽  
Acceptor Side ◽  
Photovoltaic Solar Cells

scholarly journals DFT Modelling of Tripeptides (Lysine-Tryptophan-Lysine) Interacting with Single Walled Carbon Nanotubes

2010 ◽  
Vol 7 (3) ◽  
pp. 870-874 ◽  
Author(s):  
Navaratnarajah Kuganathan
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Density Functional ◽  
Single Walled Carbon Nanotubes ◽  
Binding Energies ◽  
Functional Theory ◽  
Model Calculations ◽  
Walled Carbon Nanotubes ◽  
Dft Modelling ◽  
Covalent Nature

Model calculations are performed to predict the nature of interaction between SWNT and a tripeptide (Lys-Trp-Lys) and to calculate the binding energies and charge transfer between these two species using density functional theory. DFT calculations indicate that the interaction is of a non covalent nature. Minimal charge transfer is observed between SWNT and Lys-Trp-Lys.

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