Related Experiment Video
Updated: Jul 1, 2025
08:12
Low Pressure Vapor-assisted Solution Process for Tunable Band Gap Pinhole-free Methylammonium Lead Halide Perovskite Films
Published on: September 8, 2017
9.6K
Kinetic Process with Anti-Frenkel Disorder in a CsPbI3 Perovskite
Taoyuze Lv1, Yuhang Liang2, Fang Zeng1
1School of Physics, The University of Sydney, Sydney, NSW 2006, Australia.
The Journal of Physical Chemistry Letters
|March 7, 2024
Summary
Iodide vacancies and interstitials in halide perovskites lower the energy barrier for creating more anti-Frenkel disorder. This defect behavior facilitates long-range annihilation and hopping processes in these materials.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Perovskite Materials
Background:
- Halide perovskites exhibit significant ionic diffusion due to low activation energies.
- The soft lead iodide lattice in perovskites allows for complex defect interactions.
Purpose of the Study:
- To investigate the hopping mechanics of iodide interstitials in halide perovskites.
- To understand the relationship between iodide interstitials and anti-Frenkel disorder.
- To determine the energetic barriers for defect creation and annihilation.
Main Methods:
- Systematic investigation of iodide interstitial hopping.
- Analysis of anti-Frenkel disorder creation and annihilation.
- Computational modeling of defect free energy barriers.
Main Results:
- Iodide vacancies and interstitials reduce the creation barrier for additional anti-Frenkel disorder.
- Free energy barriers for generating new Frenkel defect pairs range from 0.25 to 0.43 eV.
- These barriers are comparable to those of intrinsic iodide defects at 300 K.
Conclusions:
- The spontaneous formation of anti-Frenkel disorder is facilitated by existing iodide defects.
- This process aids in long-range annihilation and defect hopping within the halide perovskite structure.
Related Concept Videos
01:17Pericyclic Reactions: Introduction
8.3K
Pericyclic reactions are organic reactions that occur via a concerted mechanism without generating any intermediates. The reactions proceed through the movement of electrons in a closed loop to form a cyclic transition state, where rearrangement of the σ and π bonds yields specific products.
Pericyclic reactions can be classified into three categories: electrocyclic reactions, cycloaddition reactions, and sigmatropic rearrangements. Electrocyclic reactions and sigmatropic...
Pericyclic reactions can be classified into three categories: electrocyclic reactions, cycloaddition reactions, and sigmatropic rearrangements. Electrocyclic reactions and sigmatropic...
8.3K
01:29Potential Due to a Polarized Object
403
A neutral atom consists of a positively charged nucleus surrounded by a negatively charged electron cloud. When placed in an external electric field, the external electric force pulls the electrons and nucleus apart, opposite to the intrinsic attraction between the nucleus and the electrons. The opposing forces balance each other with a slight shift between the center of masses of the nucleus and the electron cloud, resulting in a polarized atom. On the other hand, a few molecules, like water,...
403
01:34Woodward–Hoffmann Selection Rules and Microscopic Reversibility
3.1K
Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for...
3.1K
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
2.3K
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
2.3K
01:08Hückel's Rule Diagram of π MOs: Frost Circle
4.4K
The Frost circle or the inscribed polygon method is a graphical method for determining the relative energies of π molecular orbitals (MOs) for planar, fully conjugated, and monocyclic compounds. This method was first described by A. A. Frost and Boris Musulin in 1953.
A Frost circle is constructed by drawing a polygon whose number of edges is equal to the number of carbons of the given cyclic system, with one of the vertices pointing down. Then, a circle is drawn enclosing the polygon so...
A Frost circle is constructed by drawing a polygon whose number of edges is equal to the number of carbons of the given cyclic system, with one of the vertices pointing down. Then, a circle is drawn enclosing the polygon so...
4.4K
03:24Hybridization of Atomic Orbitals I
47.1K
The mathematical expression known as the wave function, ψ, contains information about each orbital and the wavelike properties of electrons in an isolated atom. When atoms are bound together in a molecule, the wave functions combine to produce new mathematical descriptions that have different shapes. This process of combining the wave functions for atomic orbitals is called hybridization and is mathematically accomplished by the linear combination of atomic orbitals. The new orbitals that...
47.1K