Halide perovskite dynamics at work: Large cations at 2D-on-3D interfaces are mobile
Related Experiment Video
Updated: Oct 1, 2025
Monovalent Cation Doping of CH3NH3PbI3 for Efficient Perovskite Solar Cells
Published on: March 19, 2017
Sujit Kumar1,2,3, Lothar Houben4, Katya Rechav4
1Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot-7610001, Israel.
Abstract:
SignificanceSurface engineering of halide perovskites (HaPs), semiconductors with amazing optoelectronic properties, is critical to improve the performance and ambient stability of HaP-based solar cells and light emitting diodes (LEDs). Ultrathin layers of two-dimensional (2D) analogs of the three-dimensional (3D) HaPs are particularly attractive for this because of their chemical similarities but higher ambient stability. But do such 2D/3D interfaces actually last, given that ions in HaPs move readily-i.e., what happens at those interfaces on the atomic scale? A special electron microscopy, which as a bonus also reveals the true conditions for nondestructive analysis, shows that the large ions that are a necessary part of the 2D films can move into the 3D HaP, a fascinating illustration of panta rei in HaPs.
More Related Videos
08:12Low Pressure Vapor-assisted Solution Process for Tunable Band Gap Pinhole-free Methylammonium Lead Halide Perovskite Films
Published on: September 8, 2017
04:14Facile Synthesis of Colloidal Lead Halide Perovskite Nanoplatelets via Ligand-Assisted Reprecipitation
Published on: October 1, 2019
Related Concept Videos
02:42Ionic Crystal Structures
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
02:42Valence Bond Theory
02:48Ionic Bonding and Electron Transfer
02:54Trends in Lattice Energy: Ion Size and Charge