Ternary diagrams of the phase, optical bandgap energy and photoluminescence of mixed-halide perovskites

Se Yun Kim, Ho Chang Lee, Yujin Nam, Yeonghun Yun, Si Hong Lee, Dong Hoe Kim, Jun Hong Noh, Joon Hyung Lee, Dae Hwan Kim, Sangwook Lee, Young Woo Heo

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1 Citation (Scopus)

Abstract

Halide perovskites attract enormous attention as promising light absorption and emission materials for photovoltaics and optoelectronic applications. Here we report ternary diagrams of the phase, optical bandgap energy (Eg) and photoluminescence intensity of methylammonium lead halide (MAPbX3, where X = I, Br and Cl) perovskites, with three vertices of MAPbI3, MAPbBr3 and MAPbCl3. All the compositions were synthesized via a facile mechanochemical reaction at room temperature, to ensure the desired stoichiometries of the final products. Through structural study on MAPbX3, the phase diagram comprising a single phase region and two multi-phase regions was obtained. In the single phase region, the a-axis lattice constant increases almost linearly with increasing the average size of the X site ions. Interestingly, Eg decreases almost linearly with increasing the average size of the X site ions, giving negligible deviation from Vegard's law. As the result, a certain bandgap value, in the range of 1.55 - 2.9 eV, can be easily designed with infinite numbers of compositions. For the last, the ternary diagram of the photoluminescence intensity reveals the effective compositions for red, green and blue light emission. The comprehensive structural and optical information reported in this study is useful for designing halide perovskites for various applications. In addition, our approach for compositional mapping various characteristics using a solid-state reaction is an efficient and robust way to studying halide perovskites.

Original languageEnglish
Pages (from-to)460-469
Number of pages10
JournalActa Materialia
Volume181
DOIs
Publication statusPublished - 2019 Dec

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Keywords

  • Bandgap energy
  • Lattice constant
  • Mixed halide perovskite
  • Photoluminescence
  • Ternary phase diagram

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Polymers and Plastics
  • Metals and Alloys

Cite this

Kim, S. Y., Lee, H. C., Nam, Y., Yun, Y., Lee, S. H., Kim, D. H., Noh, J. H., Lee, J. H., Kim, D. H., Lee, S., & Heo, Y. W. (2019). Ternary diagrams of the phase, optical bandgap energy and photoluminescence of mixed-halide perovskites. Acta Materialia, 181, 460-469. https://doi.org/10.1016/j.actamat.2019.10.008