Exploiting Ionic Radii for Rational Design of Halide Perovskites

2019 ◽  
Vol 32 (1) ◽  
pp. 595-604 ◽  
Author(s):  
Runhai Ouyang
Keyword(s):  
Rational Design ◽  
Ionic Radii ◽  
Halide Perovskites

scholarly journals Assessment of Dynamic Structural Instabilities Across 24 Cubic Inorganic Halide Perovskites

2019 ◽  
Author(s):  
Ruo Xi Yang ◽  
Jonathan Skelton ◽  
E Lora Da Silva ◽  
Jarvist Moore Frost ◽  
Aron Walsh
Keyword(s):  
Group Symmetry ◽  
Stable Phase ◽  
Cubic Phase ◽  
Ionic Radii ◽  
Jahn Teller ◽  
Thermodynamic Driving Force ◽  
Halide Perovskites ◽  
Structural Instabilities ◽  
Decomposition Phase ◽  
Material Screening

<div><div>Metal halide perovskites are promising candidates for next-generation photovoltaic and optoelectronic applications. The flexible nature of the octahedral network introduces complexity when understanding their physical behavior. It has been shown that these materials are prone to decomposition, phase competition, and the local crystal structure often deviates from the average space group symmetry. To make stable phase-pure perovskites, understanding their structure-composition relations is of central importance. We demonstrate, from lattice dynamics calculations, that the 24 inorganic perovskites ABX<sub>3</sub> (A = Cs, Rb; B = Ge, Sn, Pb; X = F, Cl, Br, I) exhibit instabilities in their cubic phase. These instabilities include cation displacements, octahedral tilting, and Jahn-Teller distortions. The magnitudes of the instabilities vary depending on the chemical identity and ionic radii of the composition. The tilting instabilities are energetically dominant, and reduce as the tolerance factor increases, whereas cation displacements and Jahn-Teller type distortions depend on the interactions between the constituent ions. We further considered representative tetragonal, orthorhombic and monoclinic perovskites phases to obtain phonon-stable phases for each composition. This work provides insights into the thermodynamic driving force of the instabilities and will help guide synthesis in material screening. </div></div>

scholarly journals Assessment of Dynamic Structural Instabilities Across 24 Cubic Inorganic Halide Perovskites

2019 ◽  
Author(s):  
Ruo Xi Yang ◽  
Jonathan Skelton ◽  
E Lora Da Silva ◽  
Jarvist Moore Frost ◽  
Aron Walsh
Keyword(s):  
Group Symmetry ◽  
Stable Phase ◽  
Cubic Phase ◽  
Ionic Radii ◽  
Jahn Teller ◽  
Thermodynamic Driving Force ◽  
Halide Perovskites ◽  
Structural Instabilities ◽  
Decomposition Phase ◽  
Material Screening

<div><div>Metal halide perovskites are promising candidates for next-generation photovoltaic and optoelectronic applications. The flexible nature of the octahedral network introduces complexity when understanding their physical behavior. It has been shown that these materials are prone to decomposition, phase competition, and the local crystal structure often deviates from the average space group symmetry. To make stable phase-pure perovskites, understanding their structure-composition relations is of central importance. We demonstrate, from lattice dynamics calculations, that the 24 inorganic perovskites ABX<sub>3</sub> (A = Cs, Rb; B = Ge, Sn, Pb; X = F, Cl, Br, I) exhibit instabilities in their cubic phase. These instabilities include cation displacements, octahedral tilting, and Jahn-Teller distortions. The magnitudes of the instabilities vary depending on the chemical identity and ionic radii of the composition. The tilting instabilities are energetically dominant, and reduce as the tolerance factor increases, whereas cation displacements and Jahn-Teller type distortions depend on the interactions between the constituent ions. We further considered representative tetragonal, orthorhombic and monoclinic perovskites phases to obtain phonon-stable phases for each composition. This work provides insights into the thermodynamic driving force of the instabilities and will help guide synthesis in material screening. </div></div>

Rational Design of D-π-D Hole-Transporting Materials for Efficient Perovskite Solar Cells

2021 ◽  
Author(s):  
Yangmei Ou ◽  
Lin Xie ◽  
tai wu ◽  
Rongjun Zhao ◽  
Peng Wang ◽  
...  
Keyword(s):  
Energy Source ◽  
Renewable Energy Source ◽  
Renewable Energy ◽  
Rational Design ◽  
Raw Materials ◽  
Low Cost ◽  
Perovskite Solar Cells ◽  
Hole Transporting ◽  
Halide Perovskites ◽  
Hole Transporting Materials

Organic-inorganic halide perovskites (OIHPs) are nature-abundant raw materials with prospects as a low-cost renewable energy source encouraged by the solution-processed capability of OIHPs. However, the application of expensive hole transporting...

Molecular insights on the dynamic stability of peptide nucleic acid functionalized carbon and boron nitride nanotubes

2021 ◽  
Vol 23 (1) ◽  
pp. 219-228
Author(s):  
Nabanita Saikia ◽  
Mohamed Taha ◽  
Ravindra Pandey
Keyword(s):  
Nucleic Acid ◽  
Boron Nitride ◽  
Nucleic Acids ◽  
Dynamic Stability ◽  
Peptide Nucleic Acid ◽  
Rational Design ◽  
Peptide Nucleic Acids ◽  
Boron Nitride Nanotubes ◽  
Molecular Hybrids ◽  
Single Wall Nanotubes

The rational design of self-assembled nanobio-molecular hybrids of peptide nucleic acids with single-wall nanotubes rely on understanding how biomolecules recognize and mediate intermolecular interactions with the nanomaterial's surface.

Optimizing electron density of nickel sulfide electrocatalysts through sulfur vacancy engineering for alkaline hydrogen evolution

2020 ◽  
Vol 8 (35) ◽  
pp. 18207-18214
Author(s):  
Dongbo Jia ◽  
Lili Han ◽  
Ying Li ◽  
Wenjun He ◽  
Caichi Liu ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Electron Density ◽  
Rational Design ◽  
Nickel Sulfide ◽  
Catalytic Performance ◽  
Sulfide Catalysts ◽  
Sulfur Vacancy

A novel, rational design for porous S-vacancy nickel sulfide catalysts with remarkable catalytic performance for alkaline HER.

Rational design of annotine analogues with increased inhibitory activity towards acetylcholinesterase

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
ES Halldorsdottir ◽  
S Oddsson ◽  
AM Einarsdottir ◽  
B Eiriksdottir ◽  
NM Kowal ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Rational Design

Anticoagulant Activity of Hirulog™, a Direct Thrombin Inhibitor, in Humans

1993 ◽  
Vol 69 (02) ◽  
pp. 157-163 ◽  
Author(s):  
Irving Fox ◽  
Adrian Dawson ◽  
Peter Loynds ◽  
Jane Eisner ◽  
Kathleen Findlen ◽  
...  
Keyword(s):  
Rational Design ◽  
Therapeutic Potential ◽  
Anticoagulant Activity ◽  
Subcutaneous Administration ◽  
Direct Thrombin Inhibitor ◽  
Controlled Study ◽  
Thrombin Inhibitor ◽  
Thrombin Time ◽  
Thrombotic Disease ◽  
Dose Dependent

SummaryHirulog™ (BG8967) is a direct thrombin inhibitor built by rational design using the protein hirudin as a model (Maraganore et al. [1990]; Biochemistry 29: 7095–101). In order to evaluate the therapeutic potential for hirulog in the management of thrombotic disease, the tolerability and anticoagulant activity of the agent were examined in a study of human volunteers.In a randomized, placebo-controlled study (n = 54), the intravenous infusion of hirulog over 15 min showed a rapid, dose-dependent prolongation of activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT). There was a corresponding dose-dependent increase in plasma hirulog levels. The peptide was rapidly cleared with a half-life of 36 min and a total body clearance rate for the peptide of 0.43 1 kg−1 h−1. Similar activity was observed following subcutaneous injection but with sustained pharmacodynamic and pharmacokinetic behavior. There was a significant correlation between pharmacokinetic and pharmacodynamic variables for both intravenous (r = 0.8, p <0.001) and subcutaneous administration (r = 0.7, p = 0.002).To evaluate the possible interactions of aspirin on the tolerability and anticoagulant activity of intravenous hirulog, a cross-over design was employed in eight subjects. Aspirin administration did not modify the peptide’s activity. At the administered dose of 0.6 mg kg−1 h−1 for 2 h, hirulog infusion prolonged APTT from 230 to 260% baseline. The infusion of hirulog in subjects who had received aspirin was not associated with any significant changes in the template bleeding time.The final phase of the study examined the activity and tolerability of hirulog in ten subjects during prolonged intravenous infusions for up to 24 h. The peptide (0.3 mg kg−1 h−1) exhibited sustained anticoagulant activity with no evidence for a cumulative effect. During hirulog infusion, APTT was prolonged from 210 to 250% baseline.In all phases of the study, hirulog administration was generally well-tolerated.Our observations show that hirulog is an active antithrombin agent with excellent tolerability in humans. As a direct thrombin inhibitor, hirulog provides a novel approach for the management of thrombotic disease.

Development of a rational design methodology for precast concrete slender spandrel beams: Part 1, experimental results

PCI Journal ◽  
2011 ◽  
Vol 56 (2) ◽  
pp. 88-112 ◽  
Author(s):  
Gregory Lucier ◽  
Catrina Walter ◽  
Sami Rizkalla ◽  
Paul Zia ◽  
Gary Klein
Keyword(s):  
Design Methodology ◽  
Rational Design ◽  
Precast Concrete ◽  
Experimental Results
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