Controllable Polarization and Doping in Ferroelectric In2Se3 Monolayers and Heterobilayers via Intrinsic Defect Engineering

2021 ◽  
Author(s):  
Cheng Tang ◽  
Lei Zhang ◽  
Dimuthu Wijethunge ◽  
Kostya Ken Ostrikov ◽  
Aijun Du
Keyword(s):  
Intrinsic Defect ◽  
Defect Engineering

scholarly journals Simulation-Based Defect Engineering in “α-Spodumene”

2021 ◽  
Vol 5 (3) ◽  
pp. 57
Author(s):  
Sivanujan Suthaharan ◽  
Poobalasuntharam Iyngaran ◽  
Navaratnarajah Kuganathan
Keyword(s):  
Density Functional ◽  
Lithium Ion ◽  
Defect Cluster ◽  
Intrinsic Defect ◽  
Ion Diffusion ◽  
Defect Engineering ◽  
Functional Theory ◽  
Pair Potentials ◽  
Simulation Based ◽  
Defect Process

Naturally occurring lithium-rich α-spodumene (α-LiAlSi2O6) is a technologically important mineral that has attracted considerable attention in ceramics, polymer industries, and rechargeable lithium ion batteries (LIBs). The defect chemistry and dopant properties of this material are studied using a well-established atomistic simulation technique based on classical pair-potentials. The most favorable intrinsic defect process is the Al-Si anti-site defect cluster (1.08 eV/defect). The second most favorable defect process is the Li-Al anti-site defect cluster (1.17 eV/defect). The Li-Frenkel is higher in energy by 0.33 eV than the Al-Si anti-site defect cluster. This process would ensure the formation of Li vacancies required for the Li diffusion via the vacancy-assisted mechanism. The Li-ion diffusion in this material is slow, with an activation energy of 2.62 eV. The most promising isovalent dopants on the Li, Al, and Si sites are found to be Na, Ga, and Ge, respectively. The formation of both Li interstitials and oxygen vacancies can be facilitated by doping of Ga on the Si site. The incorporation of lithium is studied using density functional theory simulations and the electronic structures of resultant complexes are discussed.

scholarly journals Intrinsic Defect Engineering in Eu3+ Doped ZnWO4 for Annealing Temperature Tunable Photoluminescence

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 99 ◽  
Author(s):  
Bao-gai Zhai ◽  
Long Yang ◽  
Yuan Huang
Keyword(s):  
Optical Absorption ◽  
Thermal Annealing ◽  
Density Functional ◽  
Annealing Temperature ◽  
Intrinsic Defect ◽  
Defect Engineering ◽  
Intrinsic Defects ◽  
X Ray ◽  
Color Tunable ◽  
Co Precipitation

Eu3+ doped ZnWO4 phosphors were synthesized via the co-precipitation technique followed by subsequent thermal annealing in the range of 400–1000 °C. The phase, morphology, elemental composition, chemical states, optical absorption, and photoluminescence (PL) of the phosphors were characterized by X-ray diffraction, scanning electron microscopy, dispersive X-ray spectroscopy, X-ray photoelectron spectrometry, diffuse UV–vis reflectance spectroscopy, PL spectrophotometry, and PL lifetime spectroscopy, respectively. It is found that the PL from Eu3+ doped ZnWO4 is tunable through the control of the annealing temperature. Density functional calculations and optical absorption confirm that thermal annealing created intrinsic defects in ZnWO4 lattices play a pivotal role in the color tunable emissions of the Eu3+ doped ZnWO4 phosphors. These data have demonstrated that intrinsic defect engineering in ZnWO4 lattice is an alternative and effective strategy for tuning the emission color of Eu3+ doped ZnWO4. This work shows how to harness the intrinsic defects in ZnWO4 for the preparation of color tunable light-emitting phosphors.

Engineering Porosity Through Defects in a Giant Pore Metal–Organic Framework

2020 ◽  
Author(s):  
Adam Sapnik ◽  
Duncan Johnstone ◽  
Sean M. Collins ◽  
Giorgio Divitini ◽  
Alice Bumstead ◽  
...  
Keyword(s):  
Distribution Function ◽  
Ball Milling ◽  
Local Structure ◽  
Pair Distribution Function ◽  
Function Analysis ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Defect Engineering ◽  
Metal Organic ◽  
Unsaturated Metal Sites

<p>Defect engineering is a powerful tool that can be used to tailor the properties of metal–organic frameworks (MOFs). Here, we incorporate defects through ball milling to systematically vary the porosity of the giant pore MOF, MIL-100 (Fe). We show that milling leads to the breaking of metal–linker bonds, generating more coordinatively unsaturated metal sites, and ultimately causes amorphisation. Pair distribution function analysis shows the hierarchical local structure is partially</p><p>retained, even in the amorphised material. We find that the solvent toluene stabilises the MIL-100 (Fe) framework against collapse and leads to a substantial rentention of porosity over the non-stabilised material.</p>

Defect engineering in SiC technology for high-voltage power devices

2020 ◽  
Vol 13 (12) ◽  
pp. 120101
Author(s):  
Tsunenobu Kimoto ◽  
Heiji Watanabe
Keyword(s):  
High Voltage ◽  
Defect Engineering ◽  
Power Devices

Universal Approach toward Hysteresis-Free Perovskite Solar Cell via Defect Engineering

2018 ◽  
Vol 140 (4) ◽  
pp. 1358-1364 ◽  
Author(s):  
Dae-Yong Son ◽  
Seul-Gi Kim ◽  
Ja-Young Seo ◽  
Seon-Hee Lee ◽  
Hyunjung Shin ◽  
...  
Keyword(s):  
Solar Cell ◽  
Perovskite Solar Cell ◽  
Defect Engineering ◽  
Universal Approach

scholarly journals Correction: Intrinsic defect formation and the effect of transition metal doping on transport properties in a ductile thermoelectric material α-Ag2S: a first-principles study

2021 ◽  
Author(s):  
Ho Ngoc Nam ◽  
Ryo Yamada ◽  
Haruki Okumura ◽  
Tien Quang Nguyen ◽  
Katsuhiro Suzuki ◽  
...  
Keyword(s):  
Transition Metal ◽  
Transport Properties ◽  
Thermoelectric Material ◽  
First Principles ◽  
Defect Formation ◽  
Chem Phys ◽  
Intrinsic Defect ◽  
Transition Metal Doping ◽  
Metal Doping ◽  
First Principles Study

Correction for ‘Intrinsic defect formation and the effect of transition metal doping on transport properties in a ductile thermoelectric material α-Ag2S: a first-principles study’ by Ho Ngoc Nam et al., Phys. Chem. Chem. Phys., 2021, DOI: 10.1039/d0cp06624a.

Defect engineering and characterization of active sites for efficient electrocatalysis

Nanoscale ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 3327-3345
Author(s):  
Xuecheng Yan ◽  
Linzhou Zhuang ◽  
Zhonghua Zhu ◽  
Xiangdong Yao
Keyword(s):  
Transition Metal ◽  
Active Sites ◽  
Defect Engineering ◽  
Metal Free

This review highlights recent advancements in defect engineering and characterization of both metal-free carbons and transition metal-based electrocatalysts.

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