Temperature-Dependent Interplay between Structural and Charge Carrier Dynamics in CsMAFA-Based Perovskites

Jiashang Zhao, Xiaohui Liu, Zijin Wu, Bahiya Ibrahim, Jos Thieme, Geert Brocks, Shuxia Tao, Lars J. Bannenberg, Tom J. Savenije*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

1 Citation (Scopus)
4 Downloads (Pure)

Abstract

State-of-the-art triple cation, mixed halide perovskites are extensively studied in perovskite solar cells, showing very promising performance and stability. However, an in-depth fundamental understanding of how the phase behavior in Cs0.05FA0.85MA0.10Pb(I0.97Br0.03)3 (CsMAFA) affects the optoelectronic properties is still lacking. The refined unit cell parameters a and c in combination with the thermal expansion coefficients derived from X-ray diffraction patterns reveal that CsMAFA undergoes an α–β phase transition at ≈280 K and another transition to the γ-phase at ≈180 K. From the analyses of the electrodeless microwave photoconductivity measurements it is shown that shallow traps only in the γ-phase negatively affect the charge carrier dynamics. Most importantly, CsMAFA exhibits the lowest amount of microstrain in the β-phase at around 240 K, corresponding to the lowest amount of trap density, which translates into the longest charge carrier diffusion length for electrons and holes. Below 200 K a considerable increase in deep trap states is found most likely related to the temperature-induced compressive microstrain leading to a huge imbalance in charge carrier diffusion lengths between electrons and holes. This work provides valuable insight into how temperature-dependent changes in structure affect the charge carrier dynamics in FA-rich perovskites.

Original languageEnglish
Number of pages13
JournalAdvanced functional materials
Early online date22 Dec 2023
DOIs
Publication statusE-pub ahead of print/First online - 22 Dec 2023

Keywords

  • charge carrier dynamics
  • metal halide perovskites
  • microstrain
  • phase structure
  • shallow trap states
  • time-resolved microwave conductivity
  • UT-Hybrid-D

Fingerprint

Dive into the research topics of 'Temperature-Dependent Interplay between Structural and Charge Carrier Dynamics in CsMAFA-Based Perovskites'. Together they form a unique fingerprint.

Cite this