Related Experiment Video
Updated: Sep 6, 2025
04:14
Facile Synthesis of Colloidal Lead Halide Perovskite Nanoplatelets via Ligand-Assisted Reprecipitation
Published on: October 1, 2019
13.1K
Passivating Lead Halide Perovskites Using Pyridinium Salts with Superhalogen Atoms
Tingwei Zhou1, Kejie Wang1, Dongjie Zhu1
1Chongqing key Laboratory of Micro&Nano Structure Optoelectronics, School of Physical Science and Technology, Southwest University, Chongqing 400715, China.
The Journal of Physical Chemistry Letters
|June 27, 2022
Summary
Pyridinium salts can passivate lead halide perovskites. C5NH6BF4 pyridinium salt offers excellent surface passivation for CsPbI3, CH3NH3PbI3, and NH2CHNH2PbI3 perovskites, enhancing device performance and stability.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Photovoltaics
Background:
- Lead halide perovskites are promising for solar cells but suffer from surface defects.
- Pyridinium salts are explored for surface passivation to improve perovskite stability and efficiency.
- Achieving excellent passivation with a single pyridinium salt remains a challenge.
Purpose of the Study:
- To systematically investigate the surface passivation of cubic CsPbI3, CH3NH3PbI3, and NH2CHNH2PbI3 perovskites using various pyridinium salts (C5NH6X, X = Cl, Br, I, PF6, ClO4, BF4).
- To identify pyridinium salts that provide excellent surface passivation, leading to improved device performance.
Main Methods:
- High-throughput first-principle calculations.
- Ab initio molecular dynamics simulations.
Main Results:
- The pyridinium salt C5NH6BF4 achieved excellent surface passivation for all three perovskites, indicated by shallow defect levels, negative formation energy, preserved band-edge structure, and stable dynamics.
- C5NH6ClO4 and C5NH6PF6 showed beneficial passivation only for the (001) PbI2 plane.
- Other C5NH6X salts exhibited adverse effects on passivation.
Conclusions:
- C5NH6BF4 is a highly effective pyridinium salt for passivating CsPbI3, CH3NH3PbI3, and NH2CHNH2PbI3 perovskites.
- This passivation strategy promises enhanced device performance, including long-term stability, reduced ion migration, and high efficiency.
- Careful selection of pyridinium salts is crucial for effective perovskite surface passivation.
Related Concept Videos
02:45Alkyl Halides
17.3K
Structural Properties
Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as fluorine, chlorine, bromine, or iodine. The carbon atom in an alkyl halide is bonded to the halogen atom, which is sp3-hybridized and exhibits a tetrahedral shape.
Unlike alkyl halides, compounds in which a halogen atom is bonded to an sp2 -hybridized carbon atom of a carbon-carbon double bond (C=C) are called vinyl halides. Whereas aryl...
Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as fluorine, chlorine, bromine, or iodine. The carbon atom in an alkyl halide is bonded to the halogen atom, which is sp3-hybridized and exhibits a tetrahedral shape.
Unlike alkyl halides, compounds in which a halogen atom is bonded to an sp2 -hybridized carbon atom of a carbon-carbon double bond (C=C) are called vinyl halides. Whereas aryl...
17.3K
00:51Base-Promoted α-Halogenation of Aldehydes and Ketones
3.6K
α-Halogenation of aldehydes and ketones is a reaction involving the substitution of α hydrogens with halogens in the presence of a base. The reaction begins with the abstraction of α hydrogen by the base to produce a nucleophilic enolate ion. This intermediate undergoes a subsequent nucleophilic substitution with the halogen to produce a monohalogenated carbonyl compound. If the starting substrate has more than one α hydrogen, it is difficult to stop the reaction...
3.6K
02:46Halogenation of Alkenes
16.4K
Halogenation is the addition of chlorine or bromine across the double bond in an alkene to yield a vicinal dihalide. The reaction occurs in the presence of inert and non-nucleophilic solvents, such as methylene chloride, chloroform, or carbon tetrachloride.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
16.4K
01:11Reactions at the Benzylic Position: Halogenation
2.7K
Benzylic halogenation takes place under conditions that favor radical reactions such as heat, light, or a free radical initiator like peroxide.
2.7K
01:26Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
1.9K
Radical substitution reactions can be used to remove functional groups from molecules. The hydrogenolysis of alkyl halides is one such reaction, where the weak Sn–H bond in tributyltin hydride reacts with alkyl halides to form alkanes. Here, the reagent Bu3SnH yields tributyltin halide as a byproduct.
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation...
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation...
1.9K
02:35Electrophilic Addition to Alkynes: Hydrohalogenation
10.3K
Electrophilic addition of hydrogen halides, HX (X = Cl, Br or I) to alkenes forms alkyl halides as per Markovnikov's rule, where the hydrogen gets added to the less substituted carbon of the double bond. Hydrohalogenation of alkynes takes place in a similar manner, with the first addition of HX forming a vinyl halide and the second giving a geminal dihalide.
10.3K