Phase diagram and stability of mixed-cation lead iodide perovskites: A theory and experiment combined study

Xu Z, Zhao Y, Zhang J, Chen K, Brabec C, Feng Y (2020)

Publication Type: Journal article

Publication year: 2020

Journal

Physical Review Materials American Physical Society

Book Volume: 4

Journal Issue: 9

DOI: 10.1103/PhysRevMaterials.4.095401

Abstract

Alloying structurally similar perovskites to form mixed-cation lead iodide perovskites, e.g., Cs(x)FA((1-x))PbI(3), MA(x)FA((1-x))PbI(3), and Cs(x)MA(y)FA((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 FAPbI(3)/MAPbI(3) matrix; otherwise it will be separated into delta-CsPbI3, delta-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 FAPbI(3)-based multication perovskites, moreover, over 10 mol % alloying is needed to convert delta phase to alpha 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 Cs(x)MA(y)FA((1-x-y))PbI(3), 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.

Authors with CRIS profile

Yicheng Zhao Institute Materials for Electronics and Energy Technology (i-MEET) Jiyun Zhang Institute Materials for Electronics and Energy Technology (i-MEET) Christoph Brabec Institute Materials for Electronics and Energy Technology (i-MEET)

Involved external institutions

Hunan University / Húnán Dàxué CN China (CN)

How to cite

APA:

Xu, Z., Zhao, Y., Zhang, J., Chen, K., Brabec, C., & Feng, Y. (2020). Phase diagram and stability of mixed-cation lead iodide perovskites: A theory and experiment combined study. Physical Review Materials, 4(9). https://dx.doi.org/10.1103/PhysRevMaterials.4.095401

MLA:

Xu, Zhengwei, et al. "Phase diagram and stability of mixed-cation lead iodide perovskites: A theory and experiment combined study." Physical Review Materials 4.9 (2020).

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