Cation engineering provides a route to control the structure and properties of hybrid halide perovskites, which has resulted in the highest performance solar cells based on mixtures of Cs, methylammonium, and formamidinium. Here, we present a multi-technique experimental and theoretical study of structural phase transitions, structural phases and dipolar dynamics in the mixed methylammonium/dimethylammonium MADMAPbBr hybrid perovskites (0 ≤ x ≤ 1). Our results demonstrate a significant suppression of the structural phase transitions, enhanced disorder and stabilization of the cubic phase even for a small amount of dimethylammonium cations. As the dimethylammonium concentration approaches the solubility limit in MAPbBr, we observe the disappearance of the structural phase transitions and indications of a glassy dipolar phase. We also reveal a significant tunability of the dielectric permittivity upon mixing of the molecular cations that arises from frustrated electric dipoles.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7547736 | PMC |
| http://dx.doi.org/10.1038/s41467-020-18938-z | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Versatile adhesive skin enhances robotic interactions with the environment.
Sci Adv
January 2025
School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
Electronic skins endow robots with sensory functions but often lack the multifunctionality of natural skin, such as switchable adhesion. Current smart adhesives based on elastomers have limited adhesion tunability, which hinders their effective use for both carrying heavy loads and performing dexterous manipulations. Here, we report a versatile, one-size-fits-all robotic adhesive skin using shape memory polymers with tunable rubber-to-glass phase transitions.
View Article and Find Full Text PDFGas-Phase Scattering of Transition Metal Atoms Fe, Ir, and Pt with CH, O, and CO.
J Phys Chem A
January 2025
Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fudan University, Shanghai 200438, China.
Understanding the interactions between transition metal atoms and molecules is important for the study of various related chemical and physical processes. In this study, we have investigated collisions between iron (Fe), iridium (Ir), and platinum (Pt) and the small molecules CH, O, and CO using a crossed-beam and time-sliced ion velocity map imaging technique. Elastic collisions were observed in all cases, except for collisions of Pt with O and CO.
View Article and Find Full Text PDFRapid rise in atmospheric CO marked the end of the Late Palaeozoic Ice Age.
Nat Geosci
January 2025
Department of Earth Sciences 'Ardito Desio', Università degli Studi di Milano, Milan, Italy.
Atmospheric CO is thought to play a fundamental role in Earth's climate regulation. Yet, for much of Earth's geological past, atmospheric CO has been poorly constrained, hindering our understanding of transitions between cool and warm climates. Beginning ~370 million years ago in the Late Devonian and ending ~260 million years ago in the Permian, the Late Palaeozoic Ice Age was the last major glaciation preceding the current Late Cenozoic Ice Age and possibly the most intense glaciation witnessed by complex lifeforms.
View Article and Find Full Text PDFPhase Coexistence Induced Giant Dielectric Tunability and Electromechanical Response in PbZrO Epitaxial Thin Films.
Small
January 2025
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China.
PbZrO (PZO) thin films, as a classic antiferroelectric material, have attracted tremendous attention for their excellent dielectric, electromechanical, and thermal switching performances. However, several fundamental questions remain unresolved, particularly the existence of an intermediate phase during the transition from the antiferroelectric (AFE) to ferroelectric (FE) state. Here, a phase coexistence configuration of an orthorhombic AFE phase and a tetragonal-like (T-like) phase is reported in epitaxial antiferroelectric PZO thin films, with thickness ranging from 16 to 110 nm.
View Article and Find Full Text PDFUltra-wide range control of topological acoustic waveguidesa).
J Acoust Soc Am
January 2025
Jianglu Mechanical Electrical Group Company Limited, Xiangtan 411105, China.
Topological acoustic waveguides have a potential for applications in the precise transmission of sound. Currently, there is more attention to multi-band in this field. However, achieving tunability of the operating band is also of great significance.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!