English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Methylammonium lead tribromide perovskite (CH3NH3PbBr3, or MAPbBr3) as aphotovoltaic material has attracted a great deal of recent interest. Factorsthat are important in their application in optoelectronic devices include theirfractional contribution of the composition of the materials as well as theirmicroscopic arrangement that is responsible for the formation of well-definedmacroscopic structures. CH3NH3PbBr3 assumes different polymorphs (orthorhombic,tetragonal and cubic) depending on the evolution temperature of the bulkmaterial. Density functional theory calculations have been performed onpolymorphs of CH3NH3PbBr3 to demonstrate that the H atoms on C of the methylgroup in MA entrapped within a MAPbBr3 perovskite cage are not electronicallyinnocent, as is often contended. We show here that these H atoms are involvedin attractive interactions with the surrounding bromides of corner-sharingoctahedra of the CH3NH3PbBr3 cage to form Br...H(-C) hydrogen bondinginteractions. This is analogous to the way the H atoms on N of the ammoniumgroup in MA form Br...H(-N) hydrogen bonding interactions to stabilize thestructure of CH3NH3PbBr3. Both these hydrogen bonding interactions are shown topersist regardless of the nature of the three polymorphic forms of CH3NH3PbBr3.These, together with the Br...C(-N) carbon bonding, the Br...N(-C) pnictogenbonding, and the Br...Br lump-hole type intermolecular non-covalentinteractions identified for the first time in this study, are shown to becollectively responsible for the eventual emergence of the orthorhombicgeometry of the CH3NH3PbBr3 system. These conclusions are arrived at from asystematic analysis of the results obtained from combined DFT, Quantum Theoryof Atoms in Molecules, and Reduced Density Gradient Non-Covalent Interactioncalculations carried out on the three temperature-dependent polymorphicgeometries of CH3NH3PbBr3.

Halogen in Materials Design: Revealing the Nature of Hydrogen Bonding  and Other Non-Covalent Interactions in the Polymorphic Transformations of  Methylammonium Lead Tribromide Perovskite