Related Experiment Video
Updated: Oct 16, 2025

Monovalent Cation Doping of CH3NH3PbI3 for Efficient Perovskite Solar Cells
Published on: March 19, 2017
Role of organic cation orientation in formamidine based perovskite materials
Siyu Liu1, Jing Wang2, Zhe Hu2
1Institute of Future Lighting, Academy for Engineering and Technology, Fudan University, Shanghai, 200433, China.
Abstract:
The rotation of organic cations is considered to be an important reason for the dynamic changes in stability and photoelectric properties of organic perovskites. However, the specific effect of organic cations rotation on formamidine based perovskite is still unknown. In our work, first-principles calculations based on density functional theory are used to examine the effect of the rotation of formamidine cations in FAPbI3 and FA0.875Cs0.125PbI3. We have comprehensively calculated the structure, electronic and optical properties of them. We found a coupling effect between formamidine cations rotation and cesium atom. This coupling effect changes the inclination angle of octahedron to regulate electron distribution, band gaps, and optical absorption. Hence, changing the cation orientation and substitution atom is a feasible way to dynamically adjust the energy band, dielectric constant and absorption edge of perovskite. Preparing perovskite with tunable properties is just around the corner through this way.
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
11:38Influence of Hybrid Perovskite Fabrication Methods on Film Formation, Electronic Structure, and Solar Cell Performance
Published on: February 27, 2017
Related Concept Videos
ortho–para-Directing Deactivators: Halogens
Ionic 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...
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3
π Molecular Orbitals of the Allyl Cation and Anion
Cationic Chain-Growth Polymerization: Mechanism
Directing Effect of Substituents: ortho–para-Directing Groups