Date: April 19th, 2023
A recent publication in Nature Communications, co-authored by Prof. Yaxin Zhai, sheds light on the thermal tolerance of perovskite quantum dots, which has important implications for their use in optoelectronics. We demonstrate that the thermal degradation mechanism of CsxFA1-xPbI3 perovskite quantum dots depends not only on their exact chemical composition but also on the ligand binding energy.
The researchers constructed a detailed picture of the temperature-dependent behavior of perovskite quantum dots across the composition range using in situ optical spectroscopic and structural measurements, supported by theoretical calculations. We found that Cs-rich perovskite quantum dots degrade due to a phase transition from black γ-phase to yellow δ-phase, while FA-rich perovskite quantum dots with higher ligand binding energy decompose directly into PbI2. Quantum dot growth to form large bulk size grains was observed for all perovskite quantum dots at elevated temperatures.
Interestingly, the researchers also found that FA-rich quantum dots possess stronger electron−longitudinal optical phonon coupling, which suggests that photogenerated excitons in FA-rich quantum dots have a higher probability of being dissociated by phonon scattering compared to Cs-rich quantum dots.
This new understanding of the thermal tolerance of perovskite quantum dots could help researchers design more stable and efficient optoelectronic devices. Prof. Zhai's contribution to this publication, in collaboration with researchers from Nankai University, highlights the important role of interdisciplinary collaboration in advancing materials science research.
Read the full article at Nature Communications
Shuo Wang, Qian Zhao, Abhijit Hazarika, Simiao Li, Yue Wu, Yaxin Zhai, Xihan Chen, Joseph M. Luther & Guoran Li, "Thermal tolerance of perovskite quantum dots dependent on A-site cation and surface ligand", Nature Communications 14, 2216 (2023)
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