1. Cesium Lead Iodide Perovskites
Drexel University, Chemical and Biological Engineering
Huilin Kuang, Dr. Aaron Fafarman
References
Introduction
Methods
Data/Results
Conclusion
Future Work
• Optimize electron transport in the film by
increasing the size of crystal grains and
their connectivity
• Quantify the known metastability of the
desired black, perovskite phase
• Annealing at 350˚C the material changes
from nonfunctional, yellow phase and
crystallizes into a black, polycrystalline,
conductive phase
• Cesium lead iodide black phase contains
conductive grains, but exposure to
environment and high temperatures makes
it susceptible to phase change into yellow
phase
• Changing solvent made no significant
impact on grain size
• Cesium lead iodide is best spin coated
at 1000 RPM unheated
• Cesium lead iodide changes phases at
150˚C
S. Dastidar et al., "High chloride Doping
levels stabilize the Perovskite phase of
Cesium lead iodide,” Nano Letters, vol.
16, no. 6, pp. 3563–3570, May 2016.
0
0.5
1
1.5
2
2.5
300 400 500 600 700 800
Absorbance
Wavelength (nm)
Phase Change From Increasing Temperature
RT
50C
100C
150C
Heated 150˚C , 4000 RPM Heated 150˚C , 1000 RPM
DMF/DMSO
Heated 150˚C , 1000 RPM
DMF/DMSO
Unheated , 1000 RPM
-0.1
0
0.1
0.2
0.3
0.4
0.5
500 550 600 650 700 750 800
Absorbance
Wavelength (nm)
CsPbI3 Different Spin Speed and Temperature
Zoom
1000 RT 1000 150C 2500 RT
2500 150C 4000 RT 4000 150C
Future work includes incorporating cesium
lead chloride into the films. Chloride
stabilizes the iodide and allows for better
conductivity. The method of incorporation
would be by synthesizing both CsPbI"
and CsPb Cl" nanocrystals and fusing
them together.