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New article by grad student Daniel Wines and Dr. Ataca

“Abnormal Phase Transition and Band Renormalization of Guanidinium-Based Organic–Inorganic Hybrid Perovskite”

Han Li, Daniel Wines, Bin Chen, Kentaro Yumigeta, Yasir Mohammed Sayyad, Jan Kopaszek, Sui Yang, Can Ataca, Edward H. Sargent, and Sefaattin Tongay

STEAM Lab members Daniel Wines and Dr. Ataca and experimental collaborators from Arizona State University and University of Toronto investigate pressure driven phase transitions and band gap renormalization of 1D and 2D Guanidinium-based organic–inorganic hybrid perovskites.

ACS Applied Materials and Interfaces

URL: https://pubs.acs.org/doi/abs/10.1021/acsami.1c14521

Abstract: Low-dimensional organic–inorganic hybrid perovskites have attracted much interest owing to their superior solar conversion performance, environmental stability, and excitonic properties compared to their three-dimensional (3D) counterparts. Among reduced-dimensional perovskites, guanidinium-based perovskites crystallize in layered one-dimensional (1D) and two-dimensional (2D). Here, our studies demonstrate how the dimensionality of the hybrid perovskite influences the chemical and physical properties under different pressures (i.e., bond distance, angle, vdW distance). Comprehensive studies show that 1D GuaPbI3 does not undergo a phase transition even up to high pressures (∼13 GPa) and its band gap monotonically reduces with pressure. In contrast, 2D Gua2PbI4 exhibits an early phase transition at 5.5 GPa and its band gap follow nonmonotonic pressure response associated with phase transition as well as other bond angle changes. Computational simulations reveal that the phase transition is related to the structural deformation and rotation of PbI6 octahedra in 2D Gua2PbI4 owing to a larger degree of freedom of deformation. The soft lattice allows them to uptake large pressures, which renders structural phase transitions possible. Overall the results offer the first insights into how layered perovskites with different dimensionality respond to structural changes driven by pressure.

Posted: September 20, 2021, 12:38 PM