Exploration of stable stoichiometries, ground-state structures, and mechanical properties of the W–Si system

This work aims to test the effectiveness of newly developed DFT-1/2 functional in calculating the electronic and optical properties of inorganic lead halide perovskites CsPbBr3. Herein, from DFT-1/2 we have obtained the direct band gap of 2.36 eV and 3.82 eV for orthorhombic bulk and 001-surface, respectively. The calculated energy band gap is in qualitative agreement with the experimental findings. The bandgap of ultra-thin film of CsPbBr3 is found to be 3.82 eV, which is more than the expected range 1.23-3.10 eV. However, we have found that the bandgap can be reduced by increasing the surface thickness. Thus, the system under investigation looks promising for optoelectronic and photocatalysis applications, due to the bandgap matching and high optical absorption in UV–Vis (Ultra violet and visible spectrum) range of electro-magnetic(em) radiation.

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“… a 43 , b 45 , 46 , c 56 , d 33 , e 64 , f 65 , g 66 , h 67 , i 68 , j 57 , k 69 , l 70 , m 71 , n 60 , o 72 , p 73 , q 59 . …”

Section: Resultsunclassified

Electronic and optical properties of bulk and surface of CsPbBr3 inorganic halide perovskite a first principles DFT 1/2 approach

Ezzeldien

Al‐Qaisi

Alrowaili

et al. 2021

Sci Rep

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“…The main goal of this method is not only to find the global and/or local minima of the free energy surface but also to screen out structures with certain properties. The CALYPSO structure prediction method based on swarm intelligence is widely used in structural searches for new materials [14], and this method has been successfully applied to various systems [15][16][17][18][19][20]. Although this method has achieved wide success, the structures produced by CALYPSO in each generation have been optimized by first-principles calculations, thus costing valuable computing resources.…”

Section: Introductionmentioning

confidence: 99%

Accelerating inverse crystal structure prediction by machine learning: A case study of carbon allotropes

et al. 2020

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Based on structure prediction method, the machine learning method is used instead of the density function theory (DFT) method to predict the material properties, thereby accelerating the material search process. In this paper, we established a data set of carbon materials by high-throughput calculation with available carbon structures obtained from the Samara Carbon Allotrope Database. We then trained an ML model that specifically predicts the elastic modulus (bulk modulus, shear modulus, and the Young's modulus) and confirmed that the accuracy is better than that of AFLOW-ML in predicting the elastic modulus of a carbon allotrope. We further combined our ML model with the CALYPSO code to search for new carbon structures with a high Young's modulus. A new carbon allotrope not included in the Samara Carbon Allotrope Database, named Cmcm-C24, which exhibits a hardness greater than 80 GPa, was firstly revealed. The Cmcm-C24 phase was identified as a semiconductor with a direct bandgap. The structural stability, elastic modulus, and electronic properties of the new carbon allotrope were systematically studied, and the obtained results demonstrate the feasibility of ML methods accelerating the material search process.

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“…The polyhedral view of crystal structure for CNO is shown in Figure 1C, from which one can see that the orthorhombic CNO consists of two basic building blocks: the edge‐shared CaO 6 and NbO 6 distorted octahedrons. In more detail, the CaO 6 octahedron monolayer and NbO 6 octahedron bilayer are alternately stacked along the a ‐axis, forming an intriguing sandwich‐type structure 17 …”

Section: Resultsmentioning

confidence: 99%

“…In more detail, the CaO 6 octahedron monolayer and NbO 6 octahedron bilayer are alternately stacked along the a-axis, forming an intriguing sandwich-type structure. 17 Figure 2A shows the band structure of CNO in the Brillouin zone, and the semiconducting nature of CNO is characterized by the calculated indirect band gap (E g ) of 3.78 eV, indicating its potential applications in optical window materials. 18 band (CTB) from O-ligands to central Nb atoms in the NbO 6 octahedrons.…”

Section: Phase Characterization and Crystal Structurementioning

confidence: 99%

High‐temperature persistent luminescence and visual dual‐emitting optical temperature sensing in self‐activated CaNb₂O₆: Tb³⁺ phosphor

et al. 2020

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The long persistent luminescence (PersL) and color adjustable properties in high‐temperature environment are of great significance for luminescent materials in the fields of multiple anti‐counterfeiting, biological imaging, and optical temperature sensing (OTS). In this work, a series of self‐activated CaNb2O6 (CNO): Tb3+ phosphors have been successfully synthesized by solid‐state reaction route, the OTS, and temperature‐dependent PersL of these phosphors is carried out and investigated in detail. Relying on the energy transfer from host to the activator Tb3+ ion, the visual color‐tunable emissions from blue to green were detected with the increase of temperature and the maximum absolute and relative sensitivities reach 0.955% K‐1 and 1.243% K‐1. Moreover, the temperature‐dependent PersL characteristics were investigated systematically, and the initial brightness and the lasting time all reach a maximum value at 323 K in the representative CNO: 1%Tb3+ sample. All the results show that the high‐temperature persistent phosphor has potential applications in OTS and anti‐counterfeiting field.

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Exploration of stable stoichiometries, ground-state structures, and mechanical properties of the W–Si system

Cited by 48 publications

References 55 publications

Electronic and optical properties of bulk and surface of CsPbBr3 inorganic halide perovskite a first principles DFT 1/2 approach

Electronic and optical properties of bulk and surface of CsPbBr3 inorganic halide perovskite a first principles DFT 1/2 approach

Accelerating inverse crystal structure prediction by machine learning: A case study of carbon allotropes

High‐temperature persistent luminescence and visual dual‐emitting optical temperature sensing in self‐activated CaNb₂O₆: Tb³⁺ phosphor

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Exploration of stable stoichiometries, ground-state structures, and mechanical properties of the W–Si system

Cited by 48 publications

References 55 publications

Electronic and optical properties of bulk and surface of CsPbBr3 inorganic halide perovskite a first principles DFT 1/2 approach

Electronic and optical properties of bulk and surface of CsPbBr3 inorganic halide perovskite a first principles DFT 1/2 approach

Accelerating inverse crystal structure prediction by machine learning: A case study of carbon allotropes

High‐temperature persistent luminescence and visual dual‐emitting optical temperature sensing in self‐activated CaNb2O6: Tb3+ phosphor

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Product

Resources

About

High‐temperature persistent luminescence and visual dual‐emitting optical temperature sensing in self‐activated CaNb₂O₆: Tb³⁺ phosphor