Journal Article

FZJ-2021-00755

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Phase diagram and stability of mixed-cation lead iodide perovskites: A theory and experiment combined study

Xu, Z. (Corresponding author) ; Zhao, Y. ; Zhang, J.Extern* ; Chen, K. ; Brabec, C. J.FZJ* ; Feng, Y.

2020
APS College Park, MD

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Please use a persistent id in citations: http://hdl.handle.net/2128/27421  doi:10.1103/PhysRevMaterials.4.095401

Abstract: Alloying structurally similar perovskites to form mixed-cation lead iodide perovskites, e.g., CsxFA(1−x)PbI3, MAxFA(1−x)PbI3, and CsxMAyFA(1−x−y)PbI3, could improve the performance of perovskite-based solar cells and light-emitting diodes. However, a phase diagram of them and a clear understanding of the underlying atomic-scale mechanism are still lacking. Using ab initio calculations combined with high-throughput experimentation, we demonstrate the phase diagram of mixed-cation lead iodide perovskites. Only a small proportion of monovalent cations (Cs+/Rb+/MA+) could be incorporated into the FAPbI3/MAPbI3 matrix; otherwise it will be separated into δ-CsPbI3, δ-RbPbI3, MAI, etc. The smaller the radius of doping cations, the harder it is to incorporate them into a perovskite lattice and the easier it is to stabilize the perovskite phase. In FAPbI3-based multication perovskites, moreover, over 10 mol % alloying is needed to convert δ phase to α phase at room temperature. The combined upper and lower limits for doping concentration restrict the appropriate alloying ratio to a narrow window. We further plot the relative energy diagram for triple-cation perovskite CsxMAyFA(1−x−y)PbI3, which reveals the ideal doping ratio for uniform stable alloying. This theory-experiment-combined study provides a clear microscopic picture of phase stability and segregation for mixed-cation perovskite solids.

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Contributing Institute(s):

1. Helmholtz-Institut Erlangen-Nürnberg Erneuerbare Energien (IEK-11)

Research Program(s):

1. 121 - Solar cells of the next generation (POF3-121) (POF3-121)
2. 540 - Advanced Engineering Materials (POF3-500) (POF3-500)

Appears in the scientific report 2021

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Essential Science Indicators ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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